1981 RESOURCE ANALYSIS / . " MANAGEMENT P'LAN

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., ~ EAST SA Y REGIONAL PARK DISTRICT

BRIONES REGIONAL PARK

RESOURCE ANALYSIS

Adopted: September 22, 1981 Resolution No: 1981-9-262

Prepared by:

East Bay Regional Park District 2950 .Peralta Oaks Court Oakland, CA 94605 (510) 635-0135 .... TABLE OF CONTENTS - continued PAGE

VII. REPORT PREPARATION AND PERSONS CONTACTED 84

A. REPORT PREPARATION 84 B. PERSONS' CONTACTED 85

VIII. BIBLIOGRAPHY-

FIGURE I. C-l: LOCATION 5 '.. FIGURE I. D-2 : AER~ PHOTOGRAPH 6 FIGURE I. E-l: MAJOR FEATURES· AND PARK NAMES 7 FIGURE III. :8-1: MASTER PLAN UNITS 14 FIGURE tV. A-I: TOPOGRAPHY 19 FIGliM tV. A-2: ASPECT 20 FIGIJRE IV. A-3: SLOPE' 21 FIGURE IV. A-4: GEOLOGY 22 FIGURE IV. A-5: GEtiLOGIC CROSS~SECTIONS 23 FIGURE IV. A-6: LANDSLIDE SUSCEPTIBILITY 24 FIGURE IV. A-7: BEDROCK DEPTH 25 FIQURE IV. A-8: EROSIO:N 26 FIGURE IV. B-1: HYDROLOGY 27 FIGURE IV. F-l: VEGETATION 44 FIGtmE IV. F-2: GRASSLAND MANAGEMENT STRATA 53 FIGURE IV. H-l: RANGE CAPABILITY 64 FIGUlm IV. I-I: wiLDFIRE-REST 'WIND 68 FIGURE IV. 1-2: WILDFlRE-NORTHEAST WIND 68 FIGURE IV. K-l: ARCHAEOLOGY -71 FIGURE V. A-I: IMPROVEHENTS 75 FIGUlm V. A-2: ROAD CROSS SECTIONS 77 FIGURE V. B-1: POTENTIAL DEVELOPMENT SITES 79 FlGURE VI. A-I: ACQUISITION 81 .

TABLES

TABLE IV. A-I: SOIL PROFILES 24 TABLE IV. B.... l: WATERSHEDS 28 TABLE IV. B"..2: AVERAGE MONTHLY FLOWS. FOR BEAR CREEK AT CONFLUENCE WITH 29 TABLE IV. C-l: SURFACE'WATER QUALITY 36 TABLE IV. C-2: GROl,JNDWAT}';R AND SPRING WATER QUALITY 37 TABLE IV. C-3: TEST WELLS .JfAT.ER QUALITY 38 TABLE IV. D-l: SUMMARY OF FREQUENCY OF WIND DIRECTION 40 TABLE IV. H-l: RANGE USE COMPARISON RAtIOS 64

ii 1981 RESOURCE SUMMARY SHEET BRIONES REGIONAL PARK

INVENTORY

LOCATION: Contra Costa County USGS QUAD: Briones Valley; Walnut Creek ACCESS: Bear Creek Rd. (west); Reliez Valley Rd. (east); Alhambra Valley Rd. (north~ SIZE: 5200 acres ELEVATION: 300-1483 feet TOPOGRAPHY: steep hills SLOPES: 0 to 75+% ROCK: sandstone; shale SOILS: clay-loam; loam CREEKS/WATERSHEDS: Ahrigo; Alexander; Alhambra; Bear; Blum; Bullseye; Grayson; Lafayette; Panorama; Reliez; Russell; Springhill; Toyon OTHER WATER: four lagoons; two cattle ponds; 13+ springs AVERAGE TEMPERATURE: 300 -1050 AIR QUALITY: Good ANNUAL PRECIPITATION: 21-25" VEGETATION: grassland; coastal brush; chaparral; oak savannah; oak woodland ; mixed hardwood/riparian forest RANGE 3000 ADM; ENDANGERED SPECIES: 3 plants; 2 animals ARCHAEOLOGY: Castanoan and Miwok hunting use HISTORY: Spanish rancho IMPROVEMENTS: two staging units; one recreation area; two group camps; internal road and trail system (46 miles); fences (over 4000 feet); corporation yard; two houses; 365 parking spaces; 20+ picnic tables; one water well; two developed springs; and 10+ chemical toilets.

MANAGEMENT

Topography is the major factor in Briones resource management. It defines watersheds for management of water and soils; influences vegetation and wildfire hazard; provides visual and accoustical isolation; and limits development of access roads and trails, utilities and facilities. Major resource management goals include: general land stewardship; provision of road and trail access; erosion control; - parkland water development to support wildlife, grazing, and visitor use; protection and restoration of diverse native vegetation and wildlife; continued use of range for grazing; protection of paleoenthological (fossil) and potential archaeological resources; control of noise and visual degradation; and control of wildfire.

MASTER PLAN UNITS

Over 90 percent of the Park is designated as in "Natural Unit". This area includes seven "Special Protection Units" and several proposed "Educational Use Units" which recognize unusual or sensitive natural or cultural resources, such as fossils, lagoons, wildflower area, creek (riparian) corridors, high-value wildlife habitat, viewpoints, or visually isolated areas. The remainder of the Park is designated as "Recreation/Staging Unit" which could be developed.

ADMINISTRATION

The Resource Analysis/Management Plan is adopted and amended by the Board of Directors. Under the zone manager, the Park supervisor will implement the }~nagement Plan with the District resource specialists. The Plan will be reviewed annually and revised each 5 'years.

iii I. INTRODUCTION

.", A. REGIONAL PARK DISTRICT

The East Bay Regional Park District (henceforth referred to as the District or EBRPD) is a special district created by the State of in 1934 covering area of approximately 1100 square miles within Contra Costa and Counties. The District owns approximately 53,000 acres of parks, wilderness, shoreline~, pres~rves, and recreation areas. The purpose of the District shall be to "acquire, develop and operate regional parklands in perpetuity for public use ~nd shall conserve these lands for the purpose of making the outdoor environment available for the enjoyment and education of the general pubiic." (District Master Plan, page 7) .

B. DISTRICT MASTER PLAN RESOURCE POLICIES AND OBJECTIVES

In order to provide direction for fulfilling the District's proper role in the community, the Board of Directors adopted a Master Plan in 1973 with revisions in 1980 listing the objectives necessary to accomplish the District's purpose. These objectives are intended to provide the public, the District Board of Directors and staff, and other governmental agencies with a clear statement of general District policies and objectives. The following excerpts from the District Master Plan deal with the District planning sequence and resource policies:

. OVERALL DISTRICT OBJECTIVES

"To provide a diversified land and water system of regional parks, recreation areas, wilderness, preserves, trails and shorelines and parkland­ related services which will provide District residents with opportunities for creative use of outdoor leisure time.

1 "Tp acquire, preserve and interpret significant examples of the natural environment, including biologic, geologic, scenic, and outdoor historic resources which exist within the boundaries of the District. "To emphasis balance of both environmental concerns and regional recreation opportunities within the system of parklands operated by the District. 1I (Page 7t

RESOURCE ANALYSIS/MANAGEMENT PLAN AND THE PLANNING SEQUENCE

Planning Sequence

The Resource Analysis/Management Plan is the second step in a four step planning sequence recommended in the District Master Plan (Page 28). The four steps are:

1. Prepare an aquisition evaluation of each property before acquisition.

2. Prepare a resource analysis which contains a resource (e.g. vegetation, wildlife, and water) management plan.

3. Prepare a land use-development plan based on the resource analysis.

4. Prepare capital development plans.

ReSource Analysis/Management Plan

According to the Master Plan:

IIAfter a parkland site has been acquired by the District and prior to the development of a land use plan, the District will complete a resource analysis which will identify features of the parkland which have significant resource value as well as provide a potential plan for vegetation and wildlife . management. Where an aquatic element is involved, a water management plan will be included. Guidelines will be established to be used in later planning processes to protect significant natural resources which could be adversely affected by parkland use." (Page, 28)

Since the most recent rev~s~on of the Master Plan (1980), the District 'has begun an effort to implement the Master Plan by assigning every <1rea

2 of parkland one of four Master Plan l1units" based on resources, educational use, and potential recreational use. The four types Master Plan units are referred to on pages 28, 33, and 34 of the Master Plan, and are: natural area units; special (resource) protection units; educational use units; and recreation/staging (developable areas) units. Recreation/Staging, Natural, and Special Protection Master Plan Units for Briones and unit management have been determined in this document. Educational Use Units are suggested, but will be established by the Board following recommendations by the District Educational Use Committee.

OTHER RESOURCE POLICIES IN THE MASTER PLAN

The District Master Plan addresses many resource-related issues and establishes policies for resource management in Chapter V. Relevant sections of this Chapter have been repeated here for the convenience of the reader of this document.

Special Protection Units

"There may be areas within all parkland classifications which contain outstanding natural features, rare or endangered plant and animal species and their supporting ecosystems, significant geological, topographical (hydrologic, visual) features (archaeological sites) or have structures of historical significance.

"Because of the unique and potentially fragile nature of these areas, Special Protective Zones (Units) shall be identified in the Resource Analysis and designated in the Land-Use Development Plans for each parkland. The primary objective of these Special Protection Zones (Units) is the preservation and enhancement of significant resources. Development within the Special Protection Zone (Units) shall be held to the minimum required for public safety protection and enhancement of the resource. Detailed restrictions of each Special Protective Zone (Unit) shall be included within the Land Use-Development Plan of each park. Prior to completion of the prescribed planning process, Environmental Preservation Zones (Special Protection Units) may be designated by the Board without benefit of a completed Resource Analysis or Land Use-Development Plan to protect sensitive areas." (Page 33)

3 Restoration of Resources

According to the Master Plan, "The District will take into consideration, as part of its land and water management program, the possiblities of reclaiming lost or altered natural biotic commun­ ities, where appropriate. Where resource analysis and land use planning indicate the benefits of restorittg marshland, grassland, woodland, forest, chaparral or other natural communities, such improvements will be included in parkland development programs." (Page 35).

Land Resource Management Policies

"The District's Land Resource Policies will provide for grazing to minimize brush encroachment and/or to reduce fuel for fire for the purposes of maintaining a healthy grassland in parkland areas where grassland is part of land use development. The' District will adhere to the highest standards of grazing management and soil and water conservation.

"Control of non-natural pest plant species (example, artichoke and star thistle) is necessary from time to time. The District shall consider the effect on people, the surrounding environment and elements of the natural community in determining the method or methods to be used in such control.

"Control of natural plants and animals (examples, baccharis and ground squirrels) is necessary from time to time. The District shall consider the effect on people, the surrounding environment and elements of the natural community and,neighboring landowners in determining both the element of control and the method or methods to be used in such control.

"Research and experimentation for the management of the District's land resource (example, regeneration of oak and other native woodlands and rare and endangered species of plants and animals) shall be undertaken as time and resources are available." (Page 34)

Environmental Hazards Policy

"In accordance with the accepted principles of ecology, the District will strive to implement an integrated pest management program which eliminates the use of chemicals as much as feasible whenever alternative methods are effective." (Page 34)

4 C. PARK LOCATION AND ACCESS

Briones Regional Park is located in Contra Costa County, California at a latitude of about 37 0 52' 30" and a longitude of about 1220 07' 30" with ~~pr80&mate5Un&~Orsal Transverse Mercator (UTM) Coordinates of 02 mN, 76 mE at the NW corner. Figure 1. C-l: "Locationll shows the regional location and access. The assessor1s parcel numbers are given in Section VI" B of this document. The Park lies generally west of the (Walnut Creek, Pleasant Hill area), north of Lafayette, and south of Martinez. The park is reached on the north from Briones Road off Alhambra Valley Road, on the southwest from Bear Creek Road, and on the eastern side from Reliez Valley Road near Withers Avenue and Pleasant Hill Road.

FIGURE I. C-l: LOCATION

This map indicates the regional location of .and road aCcess to Briones Regional Park. The figure also shows the regional drainage patterns flowing from Briones .

.~ BRIONES REGIONAL PARK location

5 D. GENERAL DESCRIPTION AND MAJOR FEATURES

Briones Regional Park is a 5200-acre parkland in the rugged located in Contra Costa County. The landscape is of steep slopes, ridge tops, and narrow valleys. The dominating feature is the high broad Briones Crest in the center of the park where panoramic views may be enjoyed. The rock in the Park are primarily sandstones and shales overlain by loam~S(ilils on the slopes and ridges, and clay soils in the valley bottoms. Briones has seven major creek systems (watersheds), many springs, and four lagoons. Vegetation is a mixture of annual grassland (includes many wildflowers), chaparral, coastal brush, oak woodland, blue-oak savannah, and mixed-hardwood/riparian forest (riparian vegetation is found along creeks). There is a high diversity of wildlife within the Park boundaries, including deer, fox, bobcat, golden eagle, white-tailed kites, newts, and many songbirds. The Park rangeland is grazed by cattle, as well as wildlife. Figure I. D-2: "Aerial Photograph" and Figure I. E-1: "Major Features and Park Names" show the area characteristics.

The area of the Park was probably used by the Costanoans and Miwok tribes of native Americans. It was formerly part of the Mexican Rancho Boca De La Canada le Pinole (ranch at the mouth of Pinole Canyon) and used for grazing by Mexican and American ranchers. Much of Briones was later designated as a watershed for local water supply.Acquisition of parkland began in 1966. Park development is limited and includes a meadow, picnic area, childrens' play area, group campsites, service roads, trails, and parking. Briones is used particularly for picnicking, hiking and horseback riding. The Park rangeland is grazed by cattle, as well as wildlife.

FIGURE I. P-2: AERIAL PHOTOGRAPH

This is a black and white aerial photograph of the area. Grassland vegetation appears light and woodland vegetation appears dark. Chaparral and shaded grassland appear gray. Water appears black.

E. PARK NAHES

The Park name "Briones" was selected to remember Don Felipe Briones and his family. The Briones lived on the property from 1829 on, petitioned the governor in 1839 for a land grant, and finally received title to the

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Sou'ce: Pac Aerial Strveys Photo #AV 1700-0!H1 5-12-79 ph 0 togr ap h three-league (13,350 acre) Boca de la Canada del Pinole (or Briones Valley Rancho) in 1852 from the U. S. District Court. Figure I. E-1: "Major Features and Park Names" is a quick reference for Park names used in this document. The names of natural resource features are also listed below followed by an indication of their origin. The names have either existed and been adopted (E) by the Park Advisory Committee (PAC) or are used in the RAMP and recommended (R) for adoption by the PAC for District. The existing names are from U. S. Geological Topographic Maps (t) or from past adopted District maps or documents (d). The recommended names are based on historical records (h), past land ownership records (0), or related existing names or features (e).

Major Features

CREEKS VALLEYS/CANYONS

Abrigo Creek (R;e) Abrigo Valley (E;d) Alexander Creek (E;d) Homestead Valley (E;d) (E;dt) Alhambra Creek Valley (R;e) Bear Creek (E;t) Lower Bear Creek Valley Buckeye Creek (R;e) Bullseye Creek (R;e) Bullseye Canyon (R;e) (E;t) Levy Creek (R;o) Panorama Creek (R;o) Panorama Canyon (E;t) Rancho Creek (R;e) Reliez Creek (E;t) Saddle Creek (R;e) San Felipe Creek (R;o) Shappel Creek (R;e) Spring Hills Creek (R;e) Toyon Creek (R;e) Toyon Canyon (E;d) Upper Bear Creek (E;t~ Bear Creek Va~ley (E;d)

LAGOONS/PONDS/WATERFALL FLATS

Sindich Lagoons (E;t) Castenoan Flat (R;e) Maricich Lagoons (E;d) Willow Flat (E;e) Hirschkind Pond (E;d) Dry Falls (R;e)

FIGURE I. E-1: MAJOR FEATURES AND PARK NAMES

The following map schematically depicts and names the major features such as topography, peaks, creeks, valleys, and roads. For trails, see Figure V. A-I.

7 ~BRIONES REGIUl\lAL I-'AHt\. major TeCllur t::t I park names

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/;fff:, i,7:1 1 ·~x;·~ Vi''AUPY' ...... { a FOND --- f'N

. RIDGES PEAKS Bald.Ridge (E;d) .. Black Oak I

..-.~ MlwokPeak. .. (R;h) , Crescent \Ridge (E;en .' Laf~yette R:idge. (E;t) Knight Peak (H; t) RUSsell Ridge (E;d) Ru.!3sell Peak (E;t)

~ ROADS/TRAILS Abr:igo Valley Trail (El Alhambra Creek Trail (E) Bear Creek'l'rail (E) Bear Valley Trail. (E) BlackO~kTrail (E) Brione.s Crest Trail (E) Crescent Ridge Trail (E) Homestead. V~leyTrail (E) Lafayette Ridge Trail (E) LagooriTrail(E) . Mar:ipo~a Trail (E) MottPeak Trail (E) Old/Briones Road Trail fE} Orchard Tra:il(E) . Pine .Tl;e:eTrail (E) Russell Peak Trail (E) SpE!llgler Trail (E) Table/Top .' Trail (E) TOY01:J.Canyon Trail (E) Wither Tr.il (R) 'Yetha Buella Trail (E)

8 II. GENERAL APPROACH FOR RESOURCE MANAGEMENT PLANNING

A. RESOURCE INVENTORY AND ANALYSIS

The foundation of knowledge necessary for resource analysis, management and planning is the RESOURCE INVENTORY. The "resource inventory" is the information available about the parkland natural and man-made features. The RESOURCE ANALYSIS is the evaluation (qualitative or quantitative) of the opportunities, constraints, or effects to be expected from any action in light of the known resource inventory. Resource inventories and analyses can be as informal as field observations made and remembered by a staff member, or as sophisticated as a more formal information system composed of the following elements:

DATA COLLECTION + DATA BASE ENTRY/STORAGE/RETRIEVAL + ANALYSES field observation writing/file drawer or library/reference studies surveys/sampling tallies/drafting/map vault/reference overlays remote sensing digitizing/magnetic tape or disk/terminal models

Two reasons for pursuing the more formal resource inventory (information system) are: to collect resource information for the Board, staff, and public use in decision:making and to avoid losing'resource knowledge or data. The EBRIS computerized data base has been used to provide opportunity for accurate comparing or modeling (combining) of different data in each area of the Park. The resource data and descriptions presented in the IIINVENTORY" sections of Resource Analysis/Management Plan is part of the more formal approach to resource inventory. The resource analyses are covered in the "ANALYSIS/MANAGEHENT II sections of the Plan.

The resource inventory changes through time because of land acquisition, wildfire, development, erosion, sedimentation, grazing, other natural events, and general human use. The resource inventory, and consequently the resource analyses should be supplemented (revised) from time to time to assure that information used for decisions is current. THIS DOCUMENT HAS BEEN PREPARED USING WORDPROCESSING AND A COMPUTER HAPPING METHOD TO ENCOURAGE PERIODIC SUPPLEMENTS OR REVISION OF THE RESOURCE INVENTORY. Analyses can be done by computer models for proposed projects or management changes at any time based on the resource inventory.

9 , B. RESOURCE MANAGEMENT PLANNING AND STRATEGY

The District staff has prepared several manuals dealing with general District-wide resource management, including: Park Operations Manual, Vegetation Management Manual, Grading Manual, Trails Manual, and Fire Department Operations Manual. These documents are general and must be applied to a park based on its resource inventory •. The park-specific resource managemen~ plan accomplishes this and covers topics not .~ addressed in a District manual.

The Briones Resource Management Plan, as presented in this document, is comprised of two major strategies (approaches) to resource management. The first, presented in "Parkland Resources" (Sections IV) and "Parkland Developments" (Section V), recognizes that different resources (e.g. rock, water, soil, vegetation, wildlife, roads, etc.) each have characteristics which should be understood and considere4 by the Board, staff, . and public when planning, developing, or managing the Park. The second, presented in "Master Plan Units and Management" (S~ction III), recognizes that resource management must be a unified program. Management strategies taken to individual resources may be in conflict with each other, so that priorities must be established. The Master Plan Units divide the Park into areas where different resource priorities prevail and identify the management considered necessary for th~ combined resource characteristics of the area.

C. GENERAL STAFF RESPONSIBILITIES FOR RESOURCE MANAGEMENT

The District Board of Directors accepts and amends the Resource Analysis/Management Plan for the Park and delegates the task of Park resource management to the General Manager. Unqer the General Manager, the Assistant General 'Manager has responsibility fot' coordinating the effortS of the various District departments in carrying out Park resource management. The Chief of Land administers leases, easements, and other legal agreements. The grazing leases and range resources are managed by the Resource Analyst (Range Specialist) in the Land Departmen·t. Resource inventory (except for some data collection), planning, and large capital improvement changes to the resources are ·performed by the the Planning & Design Department. The Chief of Plann:;i.ng and Design has assigned the resource inventory and resource planning duties to the Resource Analyst (Environmental Coordinator), and Park facility design and capital improvements to the design and engineering staff.

The Parks & Interpretation Department has day to day responsibility for Park. resource management (except for grazing leases). This responsibility runs from the Departmerit Chief to the Superintendent of Operations to the Operation Zone Manager to the Park Supervisor to the

10 .") Park crew. The Parks & Interpretation Department has two advisory resource specialists: the Land Management Specialist (concerned with service road construction/grading and vegetation management) and the Water Management Specialist (concerned with water, water quality, and fisheries) and additional operations support crews for carrying our grading and other specialized management tasks. Wildlife management recommendations are made by the Interpretive Specialist or naturalists. The procedures for Parks & Interpretation Department resource management are described in gr$ater detail in the Park Operations Manual, Section 3.6. Fire and police protection of resources are carried out in conjunction with the Public Safety Department. Prescribed burning must be authorized by the District Fire Chief.

D. RESOURCE MANAGEMENT PLAN IMPLEMENTATION AND REVIS ION

The Resource Management Plan will be implemented immediately upon acceptance by the Board of Directors. The Park Supervisor will have primary responsibility for implementing the Plan under the direction of his superiors with advisory staff assistance as needed. He will report problems, and recommend changes to the Resource Management Plan at least once each year. The job clarification and coaching plans of the Park Supervisor and members of the crew will include resource management responsibilities (see Management Cycle Manual and Park Operations Manual, Section 2.2.8). The Park Supervisor will involve the District resource specialists in a technical advisory capacity. The resource specialists will perform resource analyses and assist in recommending changes to the Resource Management Plan as needed. The Planning and Design Department will prepare a revised Resource Management Plan every five years for Board consideration and acceptance.

E. SCHEDULE AND FUNDING

Resource inventories shall be updated once annually (before May) after the adoption of the Resource Analysisl~'1anagement Plan. Resource analyses shall be performed when necessary to make management or development decisions. The Management Plan shall be updated (amended) at least every five years. Grading and fencing in the Park shall be reviewed and done on an annual basis, as necessary and feasible. Grazing leases are to be reviewed twice a year and when leases expire. Each year a list of objectives will be prepared outlining needed resource management in the Park. Funding for accomplishment of these objectives will be considered during the regular budgetary process.

11 Resource management in Briones is funded from several budgetary sources, including: Briones Park,line items; maintenance special crews; Land Department line items (e.g. range improvement expenditures); Land and Water Management Specialists' line items; and Planning & Design Department (e.g. resource inventory) line items. The grazing tenant(s), archers, and other organized groups make contributions to Briones resource management toward their goals. The expenditures for Briones can be divided into five categories: general administration; visitor assistance functions; interpretive functions; facilities maintenance functions; and resource management fuctions. The total expenditure for resource management activities in Briones is difficult to estimate; however, it is anticipated that 40 percent of all Park-related expenditures should be for this purpose. This percentage is higher than most other District parklands because of the large size of Briones, the passive character of use, and absence of major recreational and interpretive activities and facilities.

The expenditures for resource management in Briones, if broken down'by type over a long-term (50 years), should average:

Resource Inventory/Analyses 5% Service Road Grading/Maintenance 35% Wildfire Control/Prescribed Burning 10% Soils/Vegetation Management 15% Water Development & Water Quality (erosion) 20% Wildlife Habitat Improvement and Restoration 10% Range (Grazing, Fencing) From Lease Revenue As Necessary These percentages will be used to balance resource management expenditures during the budgetary process.

12 III. MASTER PLAN UNITS AND MANAGEMENT

A.UNIT DEFINITIONS AND PURPOSES

Several policies ·of the Master Plan have been combined to form the "Master Plan Units." (Planning Policies, Land Use-Development Plan, page 28; Resource Policies, Environmental Preservation Zones, page 33; Educational Use Areas, page 34; Regional Park Planning Guidelines, page 14). This resource zoning method is being implemented in all of the District's parks to guide maintenance and development. One objective of this system is to preserve important natural resources. The two basic units in which a parkland is divided are Recreation/Staging Units and the Natural Units. Recreation/Staging Units are designated in areas that have the potential for develqpment without causing major adverse affects on resources; but these units may not be fully developed after planning is completed. Special Protection Units and Educational Use Units will be a part of the Natural Unit. Management and operational procedures for the Master Plan Units are included. The definitions for each type of unit is stated below and is followed by the designation for the Briones Master Plan Units shown in Figure III. B-1: "Master Plan Units".

NATURAL UNIT

This includes the Special Protection Units, Educational Use Units and all other areas of a parkland not designated as Recreation/Staging Units. The purpose of the natural unit is "to assure protection of natural features and values within a significant portion of every District parkland"

SPECIAL PROTECTION UNIT

Any area within a parkland containing: outstanding natural features; rare or endangered plant and animal species, and their supporting ecosystems; selected samples of each plant and animal community

13 occurring naturally in the District; significant geologic, topographic, hydrologic or scenic features; archaeological sites; historical structures; or blue-line streams and other designated water courses, which, in the context of all District resources, warrant special protective management practices.

EDUCATIONAL USE UNIT

.~ An area within parklands identified by the District Educational Use Committee as appropriate for the study of natural, archaeologic, and historic features by University and College faculty and students, high ~ schools, and professional and amateur researchers. It is contemplated that sample areas of each of the major ecological communities to be found within District lands will be available for study within designated units. Guidelines for operation, maintenance, and educational use for these units will be developed by the Committee.

RECREATION/STAGING UNIT

Existing or potential area of the parkland which have potential for recreational or staging activities appropriate to the specific parkland classification, or for park-related facilities (development).

B. BRIONES UNITS AND MANAGEMENT

The Master Plan Units for Briones are listed below by category and are mapped on Figure III. B-1: Master Plan Units.

FIGURE III. B-1: MASTER PLAN UNITS

Depicted here are the three types of Master Plan Units established in this Plan. They are:

N = Natural Unit S = Special Protection Unit R = Recreation/Staging Unit

14 : BRIONI:.::; Ht:.\:iIUI'f1\L '-1'\"" IIIClOl.vl

Scuce: Pac Aerial &lveys Photo #AV 1700-Q9-21 5-12-79 plan units NATURAL UNIT

Features

All areas not designated as a Recreation/Staging Unit.

Management

Structures should be kept off of ridges and high points. Grazing should be continued at sustainable levels throughout the Park. The District's general policy is to support native vegetation and eliminate pest species, artichoke and star thistle, by any feasible control techniques. Use of chemical controls will be minimized. The basic road and trail network is adequate. In limited places rerouting_ will be necessary with closure of old routes. The District intends to maintain fire roads to County standards (15 feet wide) where necessary. All roads and trails will be maintained periodically. Riparian vegetation is rare in the Park and in California and has unusual wildlife habitat value. Therefore, the District's intention is to minimize encroachment .or disturbance of riparian areas. Wildfire control is a significant concern to the District. Aside from damage within the Park, the District is conce~ned about damage to adjacent lands from parkland wildfires. Within natural areas, wildfire offers significant benefits as well as potential damage. The District's intention is to balance minimal damage with maximum benefit. Under selected circumstances, prescribed burning may be applied. Animal populations will be managed where necessary to maintain natural population levels. Domestic animals, especially dog packs, will be eliminated from parkland when causing harassment to Park visitors or wildlife.

SPECIAL PROTECTION UNITS

Special Protection Units are part of the Park Natural Unit so the general recommendations for management of a Natural Unit apply (see above) except where amended to protect the features of the Special Protection Unit.

5-1 Crest/Lagoons Unit

Features: Sindicich and Maricich lagoons; boggy areas ~ marshes; rough-skinned newt, tiger salamander, red-legged frog, western pond turtle and white-tailed kite habitat; golden eagle roosting area; Mott Peak & Briones Peak vie~~oints; and north-south Park divide along Briones Crest.

Management: Minimize road building; maintain roads to avoid siltation of lagoons; conduct periodic dredging of lagoons to 4-10 feet deep; manage cattle to avoid shoreline deterioration of lagoons; build no structures on the peaks or crest; prevent off-road use of grassy flats by vehicles; and avoid creating barriers to newt migration from adjacent canyons to lagoons.

15 S-2 Old Briones Road Wildflower Unit

Features: Significant nature wildflowers (such as globe and Mariposa lilies, clarkias, and Dutchman's Pipe); spring water with trillium wildflowers; and ungrazed blue oak grove.

Management: Existing fence, exclosing cattle from the area, should be maintained with possible addition of fencing. near spring and trilliums. Grading ~nd aff~ets .on downslopes of roads is consistent with maiIltenance of thiS area, but should be minimized. Edcuate people about wildflowers; post and enforce uno collecting (picking)". Disturbance or rem.oval of blue oaks should be min~l.

S"'3 Alhambra Creek Riparian Unit

Features: Major riparian corridor; big~leaf Maple grove; all major vegetative cOtllIll,unities; Alhambra water tunnel; blue oak savannah; valley oaks; ~Iid grassy creek terrace s.outh of walnut orchard used by swallows and· flyca1;chers (bi.rds). ..

Management: Maintain visitationa:t limited levels; minimize disturbance of riparian corridor and vegetative conununities adjacent to it to protect wildlife habitat; build roads away from the creek when possible; protect valley oaks; avoidtypical·detriinental impacts on oaks 'from di.$t1,1rbance(e.g. road and structure construction), soil compaction, or artificial irr:i,.gation wi,thin the root zQne; do; not mow grassy terraces sO\lth of walnutorchatd durin.g the spring and early summer (to maintain bird and animal. habitat duringliesting and breeding season).

S-4 Bear Creek Valley Unit

Features: Large visually .secluded valley; mixed hardwood/riparian forest; Bear Creek watershed; and Black Oak Knob.

Management: The primary feature of Bear Creek,Valley is solitude. This seclusion should be protected by limiting intensity and frequency of visitor activity (for instance 2 limit number of group activit.ies). Both visual and acoustical intrusion by vehicles, structures and other potential noise or visual distractions should be avoided. Within the }lark, black oaks are unique, found only in this unit and should be protected against removal. The mixed hardwood/riparian forest in this area are rich and should remain largely undisturbed. The Bear Creek Valley has a significant watershed which should be protected to avoid high levels of sedimentation. .

S-5 Bear Creek Gorge Unit

Features: Deep, forested riparian gorge; significant songbird habitat; mallard nesting area for Briones Reservoir;; Coopers hawk nesting area; and great-horned owl nesting area.

Management: Minimize grading and vegetation or tree removal; maintain trails at elevated levels relative to riparian trees for birdwatching.

16 S-6 Russell Peak Wildlife Unit

Features: Butterfly breeding area; Alameda striped racer habitat; general wildlife value; Russell Peak viewpoint; and Franciscan formation geological outcrops.

Management: Planning of Homestead Valley development should protect views from Russell Peak by siting facilities behind visual barriers where possible; any vegetation management should maintain vegetative diversity of are-and not eliminate completely chaparral or other communities to protect habitat value.

S-7 Fossil Ridge Unit

Feature: This area contains valuable paleontological resources.

Management: Major grading should be done after contacting a paleontologist.

EDUCATIONAL USE UNITS

No Education Use Units are designated by this report pending review by the Education Use Committee's recommendations. Three areas are suggested:

an area near Diablo Valley College in the supper Grayson watershed and including Maricich Lagoons, an Area on Russell Ridge used by Lafayette Schools; and the Fossil Ridge

RECREATION/STAGING UNITS

General Management

Development of high-use public facilities within the Park will be limited to areas of this designation. Development will follow adoption of a Land Use Plan and approved capital development within these areas. Development in these areas should avoid: causing significant scenic impacts to the Natural Unit; changes which would cause erosion, downstream sedimentation, major alteration to creek (riparian) corridors, or significant native vegetation removal; or result in extreme wildfire hazard, water pollution, or intrusive noise.

17 R-l Bear Creek Recreation Unit

Management: Grazing livestock should be excluded from Bullseye Canyon to protect the bales of hay used by the archers.

R-2 Alhambra Creek Valley Staging Unit

Management The disturbance to this area should be kept to a m~n~mum near the creek {~iparian) corridor. The large flat areas adjacent to the Creel:s should be left unmowed where possible to allow for grazing and bird feeding. The walnut trees should be removed or pruned for public safety where necessary to provide picnicking. However, the remaining trees should be left unpruned to provide nesting habitat for woodpeckers, finches, and other song birds.

R-3 Withers Staging Area

R-4 Lafayette Ridge Staging Area

R-S Old Briones Road Staging Area

R-6 District Corporation Yard

18 BRIONES REGIONA,L PARK topography

._---"-'-__, .. " _._____ • ___ ••' ,. _. .. _ L .. _ .._ ... ,_._. CONTOUR INTERVAL 80 FEET IV. PARKLAND NATURAL RESOURCES

A. TOPOGRAPHY/GEOLOGY/SOILS

INVENTORY

Topography

Briones Park covers 5,200 acres of hilly terrain in the Briones Hills, dominated by a broad upland, referred to as the Briones Crest, which crosses the park's center and is a major watershed divide •. The crest falls off steeply on the north into three deep, heavily wooded canyons which ultimately broaden out into the Alhambra Valley. Similarly, on the east (outside park boundaries) the crest falls off steeply into the upper valleys of Grayson Creek, and into Reliez Valley (name for landslides by Spanish). On the southwest, however, the drop into Bear Creek is not so precipitous or deep. This area includes several broad valleys separated by open ridges with wooded hillsides. On the southern boundary of the park are Russell and Lafayette Ridges, which are steep, narrow ridges. Figure IV. A-I "Topography" shows the countours and

FIGURE IV. A-I: TOPOGRAPHY

This map is an edited enlargement of the "Concord" IS-minute topographic quadrangle published by U.S. Geological Survey, 1959. elevations in the Park (from a USGS IS-minute "Concord" quadrangle; 1959). Elevation data in digital form is contained in two EBRIS files: U. S. Army Digital Terrain Tapes (DTT) and U. S. Geological Survey Digital Elevation Models (DEM). These can be used for creating aspect, slope, solar inclination, and as input to various resource models (soil, vegetation, wildfire).This map is overlaid on other resource maps as a reference base map. "Aspect" is the direction a slope faces. A map of aspect shows the topographic relief of an area when opposite facing aspects are shaded similarly. Figure IV. A-2: "Aspect" (EBRIS file) shows the relief for Briones.

19 FIGURE IV.A-2: ASPECT

Aspect is the direction that a slope faces. This map has eight compass directions represented with opposite aspects shaded similarly.

Elevations within the park range from about 300 feet at Alhambra Valley to 1483 feet at Briones Peak, the highest point in the park. The Bear Creek entranceilS at 650 feet. About one-third of the park lies above 1,000 feet elevation. Flat land occupies only about 10 percent of the park's total area. Most of this is in the Bear Creek watershed and includes Abrigo Valley (40 acres), Bear Creek Valley (160 acres), Bullseye Valley (15 acres), and Homestead Valley (35 acres). Recent acquisitions at the northern end of the park have provided 25 acres of valley bottom in Alhambra Creek Valley and 30 acres along Alhambra Valley Road. Flat or gentle sloping land also occurs on the Briones Crest and at scattered points along subsidiary ridges. Slopes of 25 percent or more occupy over half the park. Figure IV. A-3: "Slope" . (EBRIS file) shows the areas included in different slope classe~ and gives the total acreage of each class.

Geology and Rock Formations

Most of Briones Park consists of fine-grained sedimentary rocks of Tertiary age, with the valleys consisting of recent Quaternary alluvium. Figure IV. A-4: "Geologyl1 (EBRIS file) and Figure IV. A-5: If Geologic Cross-sections show the rock types underlying the soil and vegetation in Briones.

The Briones rocks are from the Quaternary and Tertiary Periods of the Cenozoic era. The oldest rocks are 14 million years old from .the Miocene epoch of the Tertiary Period. They belong to the Hambre Sandstone member of the Marine Monterey Formation. The rocks were formed after the dinesaurs when mammals were evolving but before man existed.

The major portion of the park is underlaid by the Briones formation, which is primarily sandstone with some shale and traces of conglomerate. This formation is on a syncline which, due to the erosion resistance and damming effect of the sandstone, has resulted in the broad upland of the Briones Crest.

The San Pablo formation lies in the east central portion of the park. This formation is a hard sandstone forming the highest elevations of the park and containing many outcrops. A number of springs occur around the edges of this formation, some of which have been developed for domestic or agricultural use.

To the north and south of the Briones formation lies the Monterey Formation, which in the Briones Park area includes two members, the

20 BRIONt:.~ Hl::ulUNAL t"'ANr\. ---~-'-----.------_ .. CONTOUR INTERVAL 80 FEET Rodeo .shale and the Hambre,sandstone. The Briones formation again. appears on Russell and Lafayette Ridges~ with the sandstone Neroly formation (which is closely related to the San Pablo) on the lower slopes on the south sid~ of Lafayette Ridge.

FIGURE IV.A~3: SLO!,E

The J3.J.ope maP iathe percentage of vertical rise over horizontal distance. The following slope classes appear on the map:

0-10%

1O~25% 2$-5(j% 56+%

At the northern end of the park the Monterey formation terminates along .th~Frank,1in Fault or a s~specte,d.associated fault and contacts the Martinez formation, which also consist,~ of shale and sandstone. Th~.~J1;iousvalley bottOIlls~ithin the park c6nsisiof· recent . (qWi~rIl,~ry) .. alluviumcaFr;ed·by.water from· the· s~rt'ouilding hills·~· ';Pi B~~rC;ree~watershe

PaleQn1;:olo&y/Fossils/Paleoecology

Bri,onescontains manypale,0nto:J,ogic (fossil) res()\lrces in the Mont e:r ey. anP! 5riionesFormations . The ,IIfost outstanding examples lies alongtJ:le: SoutSerIis;d~ of theBrione~Crest we:;;t of MottPeak; however, other . . examplesca:n be found along R.usSell Ridge, and near Maricich Lagoon.

Pholas (boring clam)borinsl'> extend down from the pase·of the Briones '. sandstone into the top of the Monterey shale,. indicating that the seas once existed over the Briones area. Common marine "megafossils" (i.e., inverte~rateand~elatively;l,ar:ge) in.the.Briones Formation include the clams Venus and Gardi.utn ; several spe,ci,¢sc>t the scallop PectenI; and the snailsTrb'phon,Nas'$a:,~nd Siphonalia. Especially striking is the small· ancientsa,nddcHb-rAstrodapsis breweri;;;nus (modern genus is Dentraster). The extinct sea IIlB.Il1Il1cil lJesmostylus,allied to sea cows but looking like a web...;footed'rhin,o witn long tusks, s.tOtit-columned hypsodont (high-crowned) mOlars, anf;! a shoveh.. like lowe; jaw grubbing on the ocean floor, has been found in the Briones Formation. Paiepecologic

21 tsHIUI"E:~ nE:.UIVI~I"\L r I"\rtf'

CONTOUR INTERVAL 80 FEET FIGURE IV •. A-4 : GEOLOGY

This map shows the geological. formations and aliuvium found in Briories.asfollows:

Tertiary Shale of the Rodeo Formation arid Monterey Group

Tertiary Claystone and Siltstone of the Martinez Formation

Tertiary Sandstone pr~a,rily of the Briones Fornuition, but also of the San Pablo, Ner91y, C:i,erbo, and. Hambre • Formations Terd.at;'y Conglomerate Sandstone, .·· ..Claystolle and .. Siltstone··

C()arse-g~ained Ple:i,stocene Alluvium

Tertiary Siltstone and Medium-gra;ned Holocene Alluvium.

studie$ (Durham, 1950) suggest that both Monterey and Briones seas '. '. '. '. 0 .: rea.chedmaxintuiQ. surfClce temperatures of no less than 17 C. This is warme1:'tQ,an. ~nYWhereCllon~1:h,e Californ.ia coast today and c~rx:esponds to the temperatures fo:undalong the middle Ba.ja Galifornia coast today.

Fos.silevidenc~ found Sou,t:heastofMt. Diablo indicates that the upper San PfibJ.o'Formationlscontinental (land~laid), containing fossil leaves and b~n,es. and teeth qi,horses, ¢a.mels, )nastodoFlts, and batte-crushing . hyaen9i,d dogs •. Based 011 marine megClfos~ils f.ound in the upper San Pablo. Formation, the water .temperature was probably .similar to that at Los Angeles' togay. '. Corrobora,tiIlg evidence' comes 'from·"a unique fossil flora described f;rom .the. ~eroly Fomation, include baldcypress Taxodium, typel.oNYfissa, redha,y Persea~ Magnolia and other relatives of tr.ees now found growing in the Squtheastefn United States. These flot,'aindicate that Biionef?Was Orily slightly~atnier ,but wetter (frequent, continuous rainfall) anti with mild'er winters than it is now. .

.Sei.smie and. Geologic. Hazards "'.

Figure IV., ~-1: "Topography" shows the three active earthquake fauits in. B:dones. The Franklin Fault crosses the northeastern portion of Briones Park in a northwest-southeast direction and is considered . potentially-active;; A. suspectedfauit trace.par.al1els the. F.ranklin Fault on the south for s:ome distance in the Briones Park areCi. The Pinole Fault lies two miles to the southwest. South of the Franklin _~ BRION~Si=l~G!5)N~~ ~~~_t\. __ geul~!:IY CONTOUR INTERVAL 80 FEET ~,I FIGURE IV. A-5: GEOLOGIC CROSS-SECTIONS

The two cross-sections transverse the Park from south to north as shown in Figure IV. A-5: "Topography".

Fault two minor faults run north-south. In Briones Park the faults generally cross rugged terrain, but the Franklin Fault crosses flat, developable land-.at.two places in the park: Alhambra. Creek Valley and Alhambra Valley proper. The fault zQne has been classified as a "High Seismic Risk Zone" in the City of Martinez General Plan. The Association of Bay Area Governments "Earthquake Study" shows the area having a probabl~ risk of damage less than "three per cent of market value" for wood frame structures.. This is a low risk.

Landsliding is the major geologic constraint on development in the park. Landslides are extensive throughout the park (see Figure IV. A-6: "Landslide Susceptibilitytl) and can restrict potential development such as construction of roads or other facilities. The lagoons area is an extensive landslide area and may be subject to creep (slow movement of earth).

Soils

Soil mapping has be~n done by the United States Soil Conservation Service a~d appears in the Contra Costa County Soil Survey. The Soil Survey divides the area into "soil series" which are areas with general the same soil characteristics of texture, composition, depth,. slope~ .erosion potential, and plant nutrients. The soil series maps are not usually meaningful to persons unless the full explanation accompanies it. It has not been reproduced here, but is available fat' reference. Instead, the soil series were input digitized EBRIS file to the computer (digitized) with three characteristics (attributes) of interest, and maps of these were produced. Soil depth to bedrock is shown in Figure IV. A-7:. "Bedrock Depth" (EBRIS file). Figure IV. A-a "Erosion" (EBRIS file) is discussed later in this Section. Figure IV. H-1 "Range . Capability" (EBRIS file) appears later in this report. Soil types in the park are primarily clays or loams. A loamy soil contains particles of three sizes: sand, silt, and clay. Clay loams of the Botella and Zamara series occur in the valley battoms. These are deep, rich soils which in the pa$t have ben utilized for unirrigated orchard or grain crops. On the Briones Crest, clay of the Tierra series occurs. This soil is very shallow of crushed fine-grained rock with poor drainage. Together with the land sliding in this area, a series of impermeable basins or lagoons have developed: and are known as the Sindicichand Maricich Lagoons. Shallow loams and clay loams of various soil series occur an the slope areas. All of these soils are considered to be "good" to "excellent" for grazing according to the U. S. Soil Conservatian Service land capability classification.

23 t1t1IUI~t:O

Prepared By: WATER RESOURCES ENGINEERS,INC. LAFAYETTE CALIFORNIA June 1967 cross-sections

®----r. ALHAMBRA~---- VALLEY FRANKLIN FAULT ---,......

ALHAMBRA VALLEY FRANKUN ----.;c:.;;.;.;..:-----. FAULT

BRIONES SYNCLINE BRIONES HILLS

BEAR CREEK VALLEY .

PINOLE ANTICUNE

ALEXANDER RANCH

BRIONES VALLEY

::E .... ::> z:;; W::> 1.>-1 W-I 0::<

N I I FIGURE IV. A-6: LANDSLIDE SUSCEPTIBILITY

This Figure shows the susceptibility of the land in Briones Park to the possibility of sliding. r:::J. No Landslides (2655 acres) E:illI 10.-30% of Area Susceptible (795 acres)

•. ~ ~ 30.-50.% of Area Susceptible (635 acres) · ... 50+% of Area Susceptible (945 acres) .... •

TABLE IV. A-1: SDIL PROFILES

Inches Parent Soil Series. A B C R Material

Botella Clay Loam 0.-8 8-52 52-68 68+ Gravel

Cropley Clay 0.,...34 none 34-60. 60+ Clay/ Lime seams

Dibble Silty Clay 0-10. 10.-30. 30.-40. 40+ Soft shale /siltstone

Los Gatos Loam 0.-8 8-27 none 27-32 Sandstone/ q.~y films

Los Dsos Clay 0.-10. 10.-32 none 32-38 Fine-grain Sandstone

Millsholm Loam 0.-4 4-12 none 12-20. Fine-grain Sandstone

Rock Dutcrop 0.-4 none none 4-10. Various

Tierra Loam 0.-25 25-71 71+ 71+

Zamora Silty Clay 0.-16 16..;.60. 60.-72 72+

Source: U.s. Soil Conservation Service, Contra Costa County Soil Survey

24 BRIONES REGIONAL PARK landslide

__~ ____ . __I!l,...... _. ______• _____.• CONTOUR INTERVAL 80 FEET susceptibility ANALYSIS/MANAGEMENT

Topography

Ridges and valleys are valuable assets for planning recreation in parklands because they can separate different sections of the park visually and accQJlstically. These topographic park divisions are reflected by the watersheds shown in Figure IV. B-1: "Hydrology". Although large scale changes to Briones' topography would be nearly impossible, topography, aspect and slope are important management factors inwate~ supply, slope failure, road grading, soil erosion, sedimentation (water quality), vegetation management wildire hazard and prevention, and gener~l recreational access, use and enjoyment. Topography generally limits development (building and vehicular access) to areas with slopes of less than 10 per cent. The park has only about 520 acres or 10 per cent of the total with slopes less than 10 per cent.

Geology and Rock Formations

The geology of Briones makes grading and earthmoving risky because the layers (strata) of alternating shales and sandstones have different hardnesses and strengths. Care must be taken when grading to avoid compounding instability.

FIGURE IV. A-7: BEDROCK DEPTH

This map shows the depth to rock indifferent areas of the Park as attribtited to each soil series in the Conta Costa County Soil Survey (U.S .. Soil Conservation Service) as foll~ws:

o-~ feet 1-1~ feet

~ ..... 1~-2 feet I22l].... 2-3~ feet [ill 3~-'5 feet 0 5+ feet

Paleontology/Fossils/Paleoecology

The fossils of Briones are important examples from the Tertiary period. Most resources are protected (hidden) by soil and rock overburden. However, past grading has uncovered some resources for educational use and allowed some vandalism. Any grading in the Special Protection Unit Seven (S-7) should be done following an invitation to a paleontologist from a local college or university to be present. Vandalism should be discouraged through public information in the park brochure.

25 BRIONES RE(:iIUNAL t"'AMf\ DtJUI U\.i~

CONTOUR INTERVAL 80 FEET Geologic Hazards

Probable risk of earthquake damage is relatively low. Buildings should be constructed to meet State standards. The risk of slope failure (landslide) is significant in steep areas. Planning should avoid placing facilities at the base of unstable slopes. The landslide risk could be increased during seismic eventsot rainstorms. Proper drainage should be instalJ.ed for all facilities. Grading on or at the "toe" of steep slopes should be minimized or avoi.ded. Earth "creep" may raise road maintenance costs and displace retaining walls or drainage works.

Soils

The deep clay soils in the valley bottoms are subject to puddling. rapid runoff, low permeability, slight erosion hazard, and severe shrink-swell potential. The clays also tend to be weak in strength and are poor for road fills and structures. Hazard of compaction is moderate and grading to depths over 5 feet is possible. Development is not_ constrained, but careful engineering is requ.ired.

The shallow clay-loam and loam soils-on the slopes are subject to high to severe erosion,rn.odetate runoff, and moderate permeability. Grading is limited by bedrock depths of less than 5 feet. Hazard of compaction and topsoil disturbance is high. Development is constrained.

The deep loams on the ridges are subject to moderate erosion hazard, moderate runoff and moderate permeability. Development is not constrained by soils.

Prescribed fire or wildfire may remoVe valuable organic -material (humus and plant litter) from the soil or cause temporary impervious soil layer. These changes would influence vegetati.on significantly.

FIGURE IV. A-8: EROSION

This map shows the soil erosion potential attributed to each soil series in the Contra Costa Soil Survey (U.S. Soil Conservation Service) as follows: .

None

Slight ~."". ~ Moderate D High

26 ~ BRIONES REGIUNAL .... AN" erO~IUII

CONTOUR INTERVAL 80 FEET B. HYDROLOGY IWATER SUPJ;'LY

~TORY

wat:~rsbeds/Dta~inat§es

~"I Briones Regiollal ~Park represents a large, nearly primitive open space (5:200 acre) are(l Within.west Contra Costa County •. Seven major . wa.tersheds·· (drainage areas) are def~n:edby the net:w6rk of· ridgeswithiIl the park. Th~ ~ajor drainag~sshown in Figure IV. B-1: . "Hydrology" (EBRIS fi1.~) are: l)A"{royo dei llaip.1;Ire anli 2) Alhambra Creek draining nod:h; 3) Pinole· and 4)~earCreeks qrainin.g west; tribl$taries to 5 r Happy valley Cree~ (Lafayettei' Creek.tributary) drainingsottth; and 6) Grayson and 7) ~Reliez Creeks draining east. Briones Crest sepaJ:ates the.:,t;:wo l~rgestdraina,g~$~, Beal;.C;reek" and Ar~oyo del Hatl;lbres (Alhambra Cre~k) • These watershe'ds dra~in~ oltei' 75 pet· c~entof the pal'k. Because the headwaters areas for alls.evenmajordrainagesare relat~vely llll,disturbed, the.park .serves i.~s an im.portant flood control watershed for s(ir~ounding ~ urban .a1:'eas .. (Marti:nez, Lafayette, Pleasant H:U.l. and :El Sobrante) a#3 recognized by the GontraCosta County'Flood C<>ntrol . District. "

FIGUB$ IV. "B"::l :~. HYDROLOGY'

., This map divides. the . Park into primary and ~ secondarywatersneds, and locates knowtl springs.

••••• Primary Watershed

..-.....Set:ondaryWatershed

.B.ear ~Creek Wat-ershed (:6BMuD ,J urlsdic tiot1)

• Springs

• Develo~ed; Springs

@ Wa.ter Well

• Livestock Watering Trough

The creeks from Briones eveIltuallydrain into or are tributary to other creeks Jlowing into the Bay system. (See Figure 1. C-1: iiLocation Map".) Arroyo del Hambre. and its ~ tributary, Alhambra Creek, enter the Bay system at Martinez Regional Shoreline. Grayson~ Reliez .and Lafayette Creeks are tributaries to. W?lnut Creek and then to Pacheco

27 BRIONt:.~ Ht:uIUNAL ~AHt\ nyarology

CONTOUR INTERVAL 80 FEET Creek, which enters the Bay system several miles east of Martinez at . Bear Creek becomes downstream of and enters the Bay system near the Standard Oil Refinery at Pt. Richmond. Pinole Creek flows northwest to the Bay system, entering at near Pionole.

TABLE IV. B-1: WATERSHEDS

Watershed Areas (Acres) Watersheds Watershed Point Secondary Primary

Arroyo Del Hambres

--Alhambra Creek at Brookwood Gate 640 --Toyon Creek at park boundary 510 --Sindicich Lagoons 35 --Maricich Lagoons 30 total in park 1,550

Bear Creek

--Abrigo Creek at Bear Creek 615 --Abrigo Creek above Dry Creek 75 --Bullseye Creek at Bear Creek 160 --Alexander Creek at Bear Creek 255 --Upper Bear Creek at Bullseye Creek 785 --Russell Creek total in park 35

at Bear Creek Road 2,000

Grayson Creek total in park 555

Happy Valley Creek

--Panorama Creek at park boundary 115

total in park 400

Pinole Creek total in park 20

Reliez Creek total in park 580

TOTAL PARK. 5,200

Source: EBRPD Estimates

The Bear Cr~ek drainage (shaded in Figure IV. B-1: "Hydrology") has special significance in that it is tributary to the East Bay Municipal Utility District (EBMUD) Briones Reservoir utilized as a reserve drinking water supply for East Bay residents. Alhambra Creek contains a

28 cave in the upper reaches of Alhambra Canyon, within park boundaries, where an attempt to develop a relatively large spring within the cave has resulted in domestic water supply for several residences located downstream and outside of park boundaries. The other major drainages do not serve as drinking water supplies but are probably utilized for some stock watering as well as providing benefits to wildlife. '

Hydrologic data for Briones Regional Park compiled by other agencies appears to be ver..;r limited according to Department of Water Resources personnel (Ritchie, personal communication). Rainfall data compiled by EBMUD for San Pablo Reservoir, located several miles west of the park indicates the average long term rainfall and evaporation rates for that Ideation are 25 inches/year and 55 inches/year, respectively. Contra Costa County Flood Control District rainfall isohyets indicate the area at the northeast corner of the park (Alhambra Creek) receives about 22.5 inches/year with a gradual increase southerly to a high of about 28 inches for the Bear Creek drainage. Discharge yields for the Upper Bear Creek watershed estimated by the rationale formula for calculations ranges between 80 and 400 acres-feet per year.

Flow rates in all creeks are seasonal with major flows during and after seasonal storm runoff events. Table IV. B-2: "Average Monthly Flows for Bear Creek at Confluence with :Briones Reservoir" contains average monthly flows for Bear Creek prior to entering Briones Reservoir based upon 15 years (1965-1980) of estimated runoff predictions compiled by EBMUD. Alhambra Creek is the only other creek that maintains summer surface flow conditions, apparently due to the Alhambra Cave Spring.

Table IV. B-2: Average Monthly Flows for Bear Creek at Confluence with Briones Reservoir*

Month Flow (ID;il. gallons)

January 380 February 260 March 210 April 120 May 40 June 20 July 10 August 10 September 30 October 30 November 80 December 120

*Based upon 15 years of data (1965-1980) compiled by EB~ruD.

29 Springs

Numerous springs (at least 13) exist within the Park but tend to be clustered along Three Lakes Fault extending north to south down the centerline of the Park and within the Alhambra and Grayson Creek drainages on the east side of the Park. (See Figure IV. B-1: "Hydrology".) Only two springs have been developed by the District to date by installation of spring boxes that serve as the domestic water supply for the n-orth entrance (Briones Road) residence. The most ..~ recently developed spring has nearly gone dry.

The City of Martinez constructed the Alhambra Creek Tunnel in the late .~ 1860' s in an effort to obtain a good water supply for the city. Upon abandonment of the tunnel, several downstream res;dents utilized and continue to utilize water piped from the tunnel. Flow from this spring in 1977 during the drought was estimated to be only 3 gpm.

Another spring box of unknown origin exists adjacent to the access road to Homestead Valley, Flow from this spring is currently less than 3 gpm. Other springs have not been developed but do provide a water source for some livestock watering ponds. The springs are manifesta­ tion of the ground water aquifers in the area. Most are apparently low-flow springs that would provide only very limited water supplies.

Ponds

Along Briones Crest, several massive landslide areas exist that have resulted in the formation of natural depressions. Two of these referred to as the Sindicich Lagoons are spring-fed which allows them to retain water even in the driest years. These two "lagoons" are unique resources in the Park providing important wildlife watering holes and are critical to a large population of newts (species?) that ha've been studied by U.C. Berkeley and are apparently endemic to that area. The surrounding woodland 'area in Toyon Canyon is also critical to the survival of this population of newts. The lagoons are currently utilized as livestock watering ponds and appear to be filling in gradually due to erosion and sedimentation processes probably accelerated by sediments transported from earthen access roads in the drainage and by activities of cattle in and around them. The tendency for cattle to linger around the lagoons results not only in accelerated erosion but in accumulations of eutrophying cow manure. The combination of sedimentation and nutrient enrichment may be causing gradual degradation of water quality in the lagoons. Mosquito fish (Gambusia affinis and goldfish (Cyprinus carpio) are known, introduced species of fish in these two lagoons.

Further to the east a similar system of swales exists and two depressions referred to as the Maricich Lagoons contain water during normal years of precipitation. The two lagoons have become dry or nearly dry during drought years, so they apparently are not spring fed.

30 Both contain introduced mosquito fish and stickleback (Gasteroteus acculeatus) and both are utilized by wildlife and livestock for drinking. Other depressions in the general area have pond water in the wet season but become dry in spring or summer.

At least two other livestock watering ponds exist in the park., A spring fed stock watering pond exists south of and near the residence at the existing corporation yard at the north end of the park. This pond contains some species of introduced warm water game fishes. A second small stock water~ng pond exists near the head of the canyon at " Homes tead Valley.

There is also a rather large stock watering pond just outside the northwest corner park boundary within the Russell property that receives season runoff from parklands which provides its water supply.

Groundwater

In 1967, the District contracted for an exploration of the groundwater to determine to' determine potential for water resources development in the park (Water Resources Engineers, 1976). This exploration consisted of test borings ranging from a depth of about 200 to 600 feet at seven different widely spaced locations. Test boring included the areas planned for future recreational development except for the Alhambra Valley entrance. The exploration failed to locate any aquifer that could be developed into a high production well. However, best water supply potentials were located within Lower Briones Sandstone deposits at the southerly end of the park at Bear Creek and Homestead Valley. A permanent well was developed at BearCreek which produced 30 gpm flow at that time. This same well was later tested by Water Management Staff for drawdown and recovery in 1977 at the end of the three-year dought (worst conditions) and it was determined that the well would yield about 600 gpd without causing sever drawdown and deterioration in water quality. The Water Resources Engineers' report recommended construction of a series of shall '(presumably 200 feet) wells that should produce 30-50 gpm, coupled with tank storage to meet the ultimate demand for water at the Bear Creek Recreation Area. The Homestead Valley test hole (T.H. 5) produced a 20 gpm flow of suitable water in 1967. The report suggests this flow would provide 40% of the water necessary to meet the demand once recreational development of that area is completed. This test hole has never been developed into a well.

Water Supply

The District will have to consider either extensive development of the groundwater supplies in the Bear Creek Recreation Area with on-site storage or will have to consider another alternative to meet the water demand for irrigation and domestic consumption. One alternative in the Bear Creek Recreation Area could be to construct a small dam in the

31 uppe~ Bear Creek drainage th~t would supply water for irrigation coupled with groundwater development for purposes of domestic consumption. Pumping of water frotn Brione.s ~servair was considered, but it is anticipated that development offacilit.i~s and pumping costs would make ..this prohibitive. . Another alternative would be to run a. pipe to . Homestead Valley fr·om the EBMuDwater tank on Russell Ridge; .. this pipe could. be left aboveground a.nd run by Siphon to' a small tank on the north side~of Russell Peak at about the same elevation as the EBMUD taq,lf. From th~egravity cou.l,dmee~ irrigation and visitor needs. in Homestead Valley.tt'hewater needs at the Alhambra Valley picnic ar.ea may require importation of water by hookup to existi'Q.g residential water supplies on Reliez Valley Road,. A limited supply of water for Alhambra .Valley might be available f:romthe Alhambra water tunnel for cattle troughs and drinking fountains if water rights c.ould. be arranged. The Briones Road staging area currently has ample water supply for drinking fountains from springs. The. water is supplied by the springs developed to accommodate water needs for the existing park residence.

ANM.YSIS /MANA,GEM,EN'I'

'. W~tersheds/])rairiages

· Ma.na,ge~~nt,()f' w:a.t~r,. water qtiality,. and erosion are usuulybest · accPmIllished by ptogratns established for each watershed or .sub,~watershed. Plc:innedimprovement,stofacilitate recrea,tional uses at Briones Regional Park are limited by topography·to iess than 10 per cent of . the tota~ park a1;'ea. '.' The;efore, .impacts associated with development wiii be limited and will probab,ly occur witlli'Q. eertain sub-drainages · within thetnajor drainages already identified,' specifically the sub-drainages of Alhambra Creek, Bear Creek, AbrigoCree, Bullseye Creek andA1e~~nd.er Creek~

Grad.~ng.tocOnS1:ruf( tb,e rO,ads ,incllldil1:S pof;sible bridge construction, and grading necess~ry to constrtlct the parking lots could result in erosion, and sedimentation as we'll as prolonged turbidity within creeks. t:nstallation of pic1:l'icta.blesaiong creeks usually results in streamside .erosion and banl< slUmping if. not located,at 1.east 50 feet away from the stream so as not to Emcaura.se use in and along the stream channel.

Concentrated v~s:itor usage by locati.~ggroup or other camps too close to stream channels could also increase erosion rates. New bridges, culver-tsar roads constructed across creeks require a Stream Alteration Permit iSsued bY1:'he Department o·f Fish and Game.

32 General Management Guidelines

Paved access roads should cross creeks by bridges as few times as possible and should be set back as far from creek channels as is practicable or a minimum of 25 feet from the channel crest.

Roads and parking lots should include. drainage systems designed with the ~~imum flow generated by a storm with the repeat freq\,ienc} of once every 10 years (10 year storm critecion) and . "'. should discharge into areas adequately protected from erosion •

Culverts or conduits should have headwalls and splash pads or other protection to prevent undercutting and erosion. (See District Grading Manual for detail.) .

All denuded slopes, cut-and-fill banks or Other disturbed sites should be seeded and mulched nol,ater than 1 OctQber to allow seed germination and some vegetative protection to control erosion prior to the normal rainy season.

Construction sites for park development should be reviewed prior to the rainy season and any structural erosion control devices deemed necessary shQuld be installed. (Ask Water Specialist for recommended erosion control structure.)

Picnic tables should be situated at least 25 feet from the crest of the stream channel and should not be grouped together to encourage concentrated disturbance of the .stream bank and channel by children or other persons.

A Stream Al.teration Permit (1601 Permit) must be obtained from the Department of Fish and Game prior to any construction activity within any distinct creek or channel.

No.loosened earthen material should be sidecast downslope from the access roadway where it 'can be carried by storm runoff into Alhambra Creek, but should be deposited in an area safe from erosion.

In the event of construction of wells for consumptive use,wells will be constructed according to code, and wells will be monitored during the dry season for drawdown and water quality as prescribed by the local health authorities. .

Development and water use within Bear Creek watershed must be cleared by the East Bay Municipal Utility District.

33 Watershed Management

The seven major drainages may be divided into numerous smaller sub-drainages for special management purposes. Figure _. ___,displays the boundaries and designates the sub-drainages of importance that have been identified. Some of the sub-drainages deserve special management consideration based upon land use (i.e., recreation/staging use) or presence of un~que or important resources (Le. Special Interest Watersheds) that will require more intense management to provide a desirable level of protection and prevent unnecessary future adverse impacts. Such activities as grading and other land disturbing activities associated with new recreational improvements, fire suppression, trail and road location or annual maintenance activities, and some grazing activities are more critical in these areas and should be carefully planned and managed.

Sub-drainages or watersheds that have been identified as special units at this time are:

Watersheds Basis for Special Management

Alhambra Creek Increased public use due to installation of parking lot, picnic tables and trailhead. Possible adverse impacts to Alhambra Creek.

Bear Creek Increased public use due to existing parking lot, meadow picnic and play area. Possible adverse impacts to Bear Creek.

Alexander Creek Increased public use due to installation of family and group picnic area, trail camp, meadows and parking lot with construction o,f improved roadway access. Possible adverse impacts to Bear Creek.

Bullseye Creek Increased public use due to installation of permanent archery range and improved roadway access. Possible adverse impacts to Bear Creek.

Abrigo Creek Installation of several group camps and graded roadway access could result in adverse impacts to Abrigo and Bear Creeks.

A waterfall unique to the area exists within unit 51A and land use activities should be consistent with preservation of this resource.

34 Watersheds Basis for Special Management

Toyon Creek An especially well developed riparian corridor with high value to wildlife and colorful wildflower display del3erve. special protection.

Sindicich Lagoons are important surface waters for wildlif~~ Land use activities

.~ could threaten the integrity of these water bodies.

Water Supply

Utilization of groundwater resources through construction of wells should cause no extensive deterioration in the water table as the water bearing sandstone deposits appear to be localized and are probably isolated limited aquifers. OVerdraft of groundwater would be aetected by monitoring the water quality of the wells. A Contra Costa County well drilling permit will be necessary. Briones has sufficient surface water to make development of a water system for park supply possible. Annual discharge (yield) from the Upper Bear Valley Creek would be sufficient to provide irrigation water at 80 to 400 acre-feet to Homestead Valley.

C. WATER QUALITY

INVENTORY

Surface Waters

Surface waters in Briones Regional Park are not extensive, consisting of at least 6 ponds (including the Sindicich and Maricich Lagoons) and a network of creeks, most of which exhibit intermittent surface flows or become completely dry in summer. Ponds have apparently never been sampled and analyzed for chemical constituents. However, as previously stated, there appears to be a gradual degradation of the Sindicich Lagoons water quality based upon visual observations.

With respect to chemical analyses of creek flows, EBMUD .conducts routine chemical analyses of Briones Reservoir water which receives inflows of water piped from the Sierras and from the Bear Creek Drainage. EBMUD staff have reported water quality of Briones Reservoir to be consistently of high quality. Also, Bear Creek (Campground Creek) was

35 t~$:tedin. 1967 1;>y W~t~rResou.r~es Engineers. Table IV .. C-I: "Surface w.ii.'i:r Qual:ity"containsresults o·f analyses on that s<;l.mple was well as .a~~lysesofa sample.collected from Alhambra Spri~g which feeds· Alhambra .Creek~. Thi$litDiteq data indicates that Bear Creek and Alhambra Creek c~htaitlgood.qtlal,ity water, at least at the sampling locations •.Sulfate cont~ntof 197 11lg/l for Beap Creek is high but ~tillwithin. the . re~onnnended California State Standard of 250 mgJI for hUIiian consumption •

.TABLE :rv.' c-l: SURFACE. WATERS QUAL1TY Alhambra Bear Const:i.tuent Spring. Creek

IDS m~/l 229 614 Umbos SPec. Condo ·em. 450 900·

Total Hardness 310 525 'a~ 'CaCe: .... ·3

Alkalinity. mg/l 68 330 asCaC03 Ca mg/l 12 76

Mg mg/l Lo5 33. Na, mg/l, 70 47

fe mg/l 1 1 F mg/l 0.1 0.1

Cl mg/l 30 60

S04 mg/l 74 197

NO" . ,3 .mg/l 1 1

From: Water Resources Engineers Report, 1967

. Groundwater

Groundwater sample analyses have been performed by Water Management staff from the well at Pear Orchard Valley and from a spring (surface ~anifestation of groundwater) at Homestead Valley and from springs which

36 supply the drinking fountain and residence at the Briones Road entrance to the Park. Table IV. C-2: contains representat.ive results of analyses on samples collected from those locations. Although moderately hard water, samples were within State Drinking Water Standards for all parameters analyzed for.

TABLE IV. C-2: GROUNDWATER AND SPRING WATER QUALITY

..~ Bear Creek Homestead North Briones Constituent Units Valley Well Valley SEring Residence SErings

-q, Alkalinity mg/l 290 160 145 as CaC03 CI mg/l 45 20 17 .5 Color units 35 25 Total Hardness mg/l 100 290 180 as CaC03 Iron mg/l 0.26 1. t.l 1. t.1 pH units 8.9 7.3 S04 mg/l 16 240 43 Turbidity FTU 8 8

In addition, Water Resources Engineers (1967) collected samples from the four test holes containing water when seven test holes were drilled in 1967 at widely spaced locations to explore the feasibility /of groundwater development. Their results (Table IV. C-3) indicate the best quality groundwater exists in the Alhambra Creek Recreation Unit (Well No.1, T.H. %, T.H. 7). As previously stated, the report recorrunends a series of shallow wells could probably be developed coupled with on-site storage to meet most of the demand for water in this major recreation area. '

ANALYSIS/MANAGEMENT

Recreational Development

Recreational development in the park could, as already stated, result in some sedimentation in creeks, adversely impacting the stream envir9ns. Silt and sediment contain varying quantities of nutrients (nitrates and phosphates) and under severe siltation conditions, the combined effects of shallowing and nutrient releases could result in algal blooms (primarily attached filamentous algae) within the stream. Provided erosion control mitigations as already recommended are implemented, it is unlikely this would be a problem. Prolonged turbidity, i. e., a

37 decrease in stream flow clarity for longer periods of time after a storm event is likely for one to two years until erosion control vegetation is well established.

Sewerage in chemical toilets is hauled from the watersheds for ultimnate disposal with no impact to water quality in the park. Two pit toilets exist in the nothern portion of the park. These should be carefully monitored and relocated on a regular basis. Generally, park development should seek to connect to sewers if availasble in the future or use holding tanks, "w1th pit toilets used only in inaccesbile areas, not in the Bear Creek watershed.

,~

TABLE IV. C-3: TEST WELLS WATER QUALITY

Well III Test Hole 3 Test Hole 5 Test Hole 7 Orchard North Abrigo Homestead No.rth Bear Constituent Units Valley Valley Valley Creek Valley

TDS 514 1158 365 321 uIDE/I os Spec. Cond 800 1700 750 cm. 850 Total Hardness mg/l 142 74 122 162 as CaC03 Alkalinity mg/l 290 207 50 50 as CaC03 Ca mg/l 54 16 65 20 Mg mg/l 1.7 3.3 20 14 Na mg/l 148 419* 14 43 Fe mg/l 1 0.1 0.1 0.1 F mg/l 0.1 tr. tr. CI mg/l 106 45 35 35 S04 mg/l, 26 470* 148 148 N0 3 mg/l I 0.1 tr. tr. *Exceeds- Recommended State Drinking Water Standards

After: Water Resources Engineers Report, 1967

Use of fertilizers and pesticides on developed irrigated meadow areas should be kept to a minimum to prevent detectable quantities of these polluting materials from escaping and entering surface or ground waters.

Groundwater resources in the Bear Creek Recreation Unit will likely be developed by installation of additional wells. To assure adequate protection from surface runoff contamination and animal access, all wells will be developed to meet Contra Costa County well standards.

38 Monito~ing of the water quality in all wells will be done according to frequency and procedures outlined by the Contra Costa County Health Department. This monitoring program will allow detection of any deterioration in water quality and will provide a record of any prolonged drawdown.

General ManagmentGuidelines

. ." Export all human wastes from the drainage (sewerage pump-out truck hauling) •

-\ . Implement erosion and sediment control recommendations as contained in Hydrology-Mitigations section of this document.

Establish a monitoring program in compliance with Contra Costa County Health requirements to periodically test groundwater wells for water quality and prolonged drawdown.

Minimize use of fertilizers and pesticides on the developed irrigated meadow areas and never exceed manufacturers recommended dosing rates.

D. CLIMATE/AIR QUALITY/NOISE

INVENTORY

Climate

The Mediterranean climate of cObl, wet winters and hot, dry summers make the park most comfortable in spring and fall. Temperature ranges from 300 - 1050 F, averaging 59 0 annually. Precipitation ranges from 9 to 36 inches and averages between 12 and 28 inches in different areas of the Park. Bear Creek receives more rain according to County rainfall maps. Wildfire season runs from late April to as late as December.

gased on information summarized in Table III. E-1: the prevailing wind conditions are probably calm and from the west most of the time. Median wind speed is about 7-10 knots (6-9 miles per hour) and maximum speeds are up to 33 knots (29 miles per mile).

39 Table IV. D-l: Summary of Frequency of Wind Direction

Station (Median SEeed in Knots) Record Direction (%) N-E ESE-SSW SW-NNW CALM

Alameda NWSF (7-10) 45-72 11 19 60 10 ,~ Berkeley L.B.L. (5) 62-68 12 37 44 7 Concord (9) 51-53 8 46 14 32 Livermore (5-10) N.A. 6 8 86 ,~ " Oakland Airport (7.5) 51-60 11 18 55 16 Pittsburg (10) 70-73 14 11 74 1 San Pablo (7) 29-39 12 25 35 28

Source: California Department of Water Resources, 1976. Summary of Wind Data

Air Quality

The site has excellent air quality. The nearby Concord air quality station had no excedences in 1980 of carbon monoxide (C)), nitrogen dioxide (N0 2), or sulfur dioxide (S02) standards. Standards were violated at Concord three days for ozone (03) and eight days for total suspended particulates (dust/ash).

Noise

The Park has very quiet ambient noi~e levels (L90) ~nd low intrusive noise levels (L IO )' The average no~se level (L 0) ~s estimated to be 35 dBA in areas more than 1600 feet from roads. TRe park contains several secluded valleys where the only intrusive noise is from aircraft (including the Park District helicopter).

ANALYSIS/MANAGEMENT

Air Quality/Noise

Two sources of air pollutants may occur from Park use: vehicle emissions (CO, NO , ozone, particulates or dust) and wildfire or prescribed fire saoke (particulates or ash). The Park air quality, as perceived by visitors, is subject to deterioration from outside air pollutant sources. In recent years, regional air quality management has

40 restored the air quality in the Briones. area, significantly reducing the number of violation days. The District should support regional air quality management to protect this Park resource.

The levels of vehicle use within and outside the Park resulting from the Plan and its projected visitation levels for Briones would probably not cause a significant increase in automobile air pollutant emissions. The vehicles of Park visitors will contribute to regional air pollutants; this is an unavoidable consequence of this land use. If vehicular, equestrian and cam-ping use is encouraged in the future, local' areas of ,'"' the Park in valleys could experience slight air quality deterioration, similar to that which has occurred in Yosemite Valley. The pollutants of concern are suspended particulates (dust and ash) and ozone. This ~ . could be exacerbated by calm wind conditions, which occur often.

Wildfire is uncontrollable and can occur on hot summer days when an inversion exists over the adjacent lands. Such an event would add to the particulate (ash) levels trapped below the inversion downwind of the fire and cause the air to look smokey. The addition of smoke could cause bad air quality to become worse. To reduce the frequency, risk and durations of these events, the District could pr~scribe-burn small areas on days designated as State Agricultural "Burn Days". Although. prescribed burning causes approximately the saJ:lle amount of particulate emission per ton of vegetation burned, the burn would occur at a time when air quality is higher and capable of handling the additional emissions of the fire.

Noise intrusion from vehicles has been minimal to date. Extension of roads into valleys will increase intrusive noise t,o up to 70 dBA at 50 feet. Vehicular noise will raise the very quiet amQient noise levels up to one-quarter mile away when no topographic barriers exist. Briones has significant topography which can be used to contain and to manage intrusive noise. The quiet areas of the Park can be left accoustically isolated if additional vehicular access roads and use of the Park are well planned. To minimize intrusive noise and the possibility of air pollution concentrations, keep vehicular use out of valleys in the Park to the extent possible.' Attempt to locate roads behind topographic barriers from secluded Park areas. A rule of thunbis that a visual barri~r functions to attenuate sound (acts as an accoustical barrier) as well; vegetation, however, is not an effective noise barrier.

41 E. ECOLOGY

INVENTORY

"Ecology" is a "branch of science concerned with the interrelationship of organisms and the.ir environments" (Webster's New Collegiate Dictionary, .1981). Briones has a relatively dry upland terrestrial . ", envirotunent wh:1.chsupports diverse number of plant and animal species • The: diversity results principally from climatic influences and topographic factors. TheParkappeaI's to be a "merg irtg " or transition zone for species from moist coastal conditiOns and drier interior (inland) areas. Ecologists find such conditions invaluable for the study of species response to gradients of various environmental factors.

Many species nonnally common to the coast are also common in Briones Park, particularly near the western boundaries of the park. Some authorities have suggested that since the Park lies directly in line of the ma.infogbanks coming 'through the ~the supplementary moiSture thus provided could account in great degree for the strong assemblage of coastal elementsiti the Park.. Also, fogs driving up the Carquinez Straits past Martinez, then drifting through the valley':'canyon plant assemblage to the northern sector probably hav-e a: sigilificant influence on the Park's vegetation. Near the Park's eastern boundaries, interior plant elements such as mountain mahogany, hop tree, Virgin's bower,dutchman'spipe, wind poppy, blue oak, valley oak, and others are found, all of which are quite connnan on nearbyMt. Diablo. With California's constant geographical and climatical fluctuations, it would be interesting to monitor changes to vegetation distributional: patterns in the future.

It seems demonstrable that Briones Park is a highly diverse· floral area, because of its steep topography of ravines and valleys, soil differences, and numerous vegetation types~ The 'variety of vegetation types and. plant speciei yields IIlany different wildlife habitat' opportunitieS for nesting, cover,migration., and food. Possibly the most in:iportant factor in the ecology of Briones is the size and isolation of the Park's natural areas. This provides enough landarea to isolate wildlife from urban disturbances and ecological productivity to support populations of large mammals and birds of prey. Such large contiguous land areas are increasingly rare. This value is increased by the proximity of Briones Park to East Bay MUD watershed lands and other undeveloped areas to the west.

Another important ecological concept is known as "edge effect", This is recognized as the boundary (transition area) -between two plant communities. The value of edge as wildlife habitat is that animals can exploit the habitat opportunities from more than one plant community. Briones offers many miles of edge. The most evident edge effect occurs along creeks where riparian vegetation (forest) passes through grassland, brush, or oak woodland.

42 ANALYSIS/~AGEMENT, ,

Because of Briones' loca,tion, size, and species diversity special care topxotectthe integrity of the large iIiteriorareas of the Park is import;ant.The, ecolo,sy' of, Briones, also provides opportunity for' e¢ucad.Qrta1a.nd ,interpretative uses in explaining pl;ant and animal rel!;PQhS~sto the,natural environment .Dev~iopmelitof, Briolles, should,be plann~a ,to avoid destroyillg ~nyspecificvegeta:r;ionor ,habitat type,. Mana&~ent of veget~ion shou3;:d maintain or increase, occurrence of, edge. '. ~ Thee4gec.reatedby riparian corridors running through relatively flat ,grasS$a.nds are in the greatest danger of being 10st)to:faci1ity development (p,arking lots, roads, etc.).

F. VEGETATION AND FLORA

INVENTORY

- '. nVegetation" for the purposes of this report describes the general clia,racteristics of the recognizable gI.'olips (-eommun;j;ties') of plants (ma,ny spec:i.ell) which may be obvious to the observer, sucn~s:grass, btllshland or forest.' "Flora" is the l±$t ofact,ual indivi,dual'plantspecie,s found in the area. ,The$e species may be fotuid in several vegetation types.

Vegetation

. ' The ,Park has ,diverse vegetativecolDJlllln:ibies. Two methods 'of maPl'ing vegetation for Briones have been fol10weq.. Figure IV.F-I: lIVegetation" a,nd the ,vegetation EBR!S file w8:s originally done tising a classified 1976 Landsat 'satellite image modeled for: dry oa:k!ba,y forest, and moist mixed hardwood sit,es by use of slope files from theEBR:r:S da.ta base Digital Terrain Tapes. The vegetationtyp¢,s were clas,sified using the California Department of Forestry 'System an.d are sivenin ;the figure caption... This Landsat: cl,assifieation has been aggregated from 80 meter (1.1 acre) pixels ... (cells o.f information) toone hec:t:a,re (100 meter or 2.47 acre) cells by ABAGfor the BASIS data base.

The Landsat information for Briones was edited using U-2 color infrared photographs (1976). The same data could be reformated for maximum resolution of 80 meter or l.l·acre cells. The value of Landsat images is not their accuracy but the frequency of area coverage. (The satellite passes over each area of the earth once every 18 days.) This makes the image ideal for monitoring vegetation change and fire conditions. Future images are expected to be more resolved and classifications will probably improve.

43 FIGURE IV. F-1: VEGETATION

This map shows the vegetation types found in Briones. The 1IlaP is derived from a 1976 Landsat satellite image which was classified bya modified CDF system of vegetation types.. It was agragated, toone hectare resolution by ABAG and modelled by EBRIS to divide the woodland and forest class by dry and moist aspect.

Hardwood; Ha,rdwood/Brush - Dry Site (600 ac)

Mixed Hardwood; Hardwood/Brush - Moist Site (880 ac) .

Conifer; Conifer/Brush; Conifer/Hardwood (42 ac) ~.' Iill.illliJ Chaparral; Coastal Brush (785 ac) r:rm1...... ~ Open Shrub (1736 ac) D Grass (985 ac) '·0 Barren (5 ac) .:::u:...... : 1lliillIT!...... Mixed Urb.an & Residential

A more accurate vegetation map was done by Scott Miner. He interpreted vegetation types from the 1970 USGS orthophoto quadrangles (Briones Valley; Walnut Creek) for the area. District staff edited this using field observation and U-2 color-infrared photos (1976). The vegetation types (classifications) are arbitrary plant associations which tend to look similar, to be located on similar sj,.tes. and to be adapted to similar environmental factors. The vegetation types usediri his vegetation map are deScribed below:

Grassland: Native and. exotic species of grasses, wildflowers, and weeds occur primarily on ridgetops, south and west-facing slopes, and flat valley bottoms. The most common exotic grass species are wild oats, wild barleys, bromes, and rye grass. The more common natives include needle grass, creeping wild rye, and onion grass. The two common weed .species are yellow star thistle and artichoke thistle.

Chaparral: This shrubby vegetation is generally found on dry, steep, rocky slopes. It is'adapted to frequent wildfires. The dominant species are chamise Adenostoma fasciculatum, toyon Heteromeles arbutifolia, and black sage Salvia mellifera, and bush monkey flower, Diplacus .aurantiacus. Some areas also include mountain mahogany Cercocarpus betuloides, and hop tree Ptelea crenulata. Outside the Park on Manzanita Ridge, manzanita Arctosaphylos crustacea occurs on Rodeo shale. .

44 ~i I::S H I U Nt:'> M I:: U I V I'J 1'\ L._____ r~l"\_c,I' I"

-.-~-- .--' CONTOUR INTERVAL 80 FEET Coastal Brush: Coastal brush is generally found on moister sites than chaparral. However, this vegetation type is quite variable in plant species composition ranging from pure stands of coyote brush on dry slopes to lush, dense thickets of poison oak on moist shaded slopes. Common species are coyote brush Baccharis pilularis var. consanguinea, poison oak Toxicodendron radicans subsp. diversilobum, California sagebrush Artimisia californica, blue elderberry Sambucus caerulea, coffeeberry Ramnus californica, oso berry Osmoronia cerasifornis, and silver bush lupine.. Lupinus albifrons.

Savannah: Blue oak Quercus douglasii, valley oak Quercus·lobata, black oak Quercus kelloggii, and buckeye Aesculus californicus, are found in open (scattered) stands on drier sites with fairly deep soil in the northeastern portion of the Park. The understory consists of grasses and herbs.

Woodland: Dense stands of coast live oak Quercus agrifolia, bay (laurel) Umbellularia californica, and buckeye. The understory may consist of the coastal brush, grassland, and less frequently, chaparral plant communities.

Forests: This community has a closed canopy and includes both mixed hardwood foreston shaded slopes with abundant. groundwater and riparian forest along creeks. The major trees include bigleaf maple Acer macrophyllum, madrone Arbutus menziesii, coast live oak,bay (laurel), buckeye, and willows Salix. Moisture-loving shrubs such as thimbleberry Rubus. parviflorus, wild blackberry Rubus vitifolius ,and California wild rose Rosa californica form the understory. During fall the forest becomes colorful as trees and shrubs shed their leaves. Notable deciduous trees are black oak, blue oak, valley oak, big leaf maple, western dogwood, hazlenut, Sierra plum and willow.

Wildflowers and Ferns

Wide expanses of grassland exist throughout the Park, and it is their character that makes forested ravines and oak studded ridges appear so profoundly and picturesquely impressive. Contained within the grassland and on bare slop~sarewildflowers such as baby blue eyes Nemophila menzieii and blue dicks Brodiaea pulchella in late winter and farewell:-to-springs Clarkia in late spring. As spring wears on into summer and fall, lizard's tail Eriophyllum lanatum and Indian paintbrush Castilleja foliosa appear. In the moister areas are shooting star Dodecatheon hendersonii and Chinese houses Collinsia heterophylla, to mention only a few.

There are many ferns in the Park in locations as diverse as deeply wooded shade and hot sunny open areas. In shade, wood fern Dryopteris arguta is most frequently found, whereas bracken fern Pteridium aquilinum var. pubescens is common to the sunny, grassy slopes.

45 Flora

The. following list contains apa.rtia1 listing of the flora of Briones Park. The list also ·identifies the plant communities in which the species is likely to be found.

A FLORA OF BRIONES

Genus. species ~ Comon N;une Habitat

Acer macrophyl1um, Big-leaved Maple F,W Achillea borea1is,Yarrow G,CB,S -\ . Achryachaena mo11is, Blow Wives G Adenostoma fascicu1atum, Ohamise C Adiantum jordani, Maidenhair F~W Aescu1us ca1ifornicus, Buckeye F,R,S Alnus rhombifo1ia, lYhi te Alder R Allocarya acanthocarpa, Adobe .. Popcorn Flower G Amsinckia intermedia, COD!lllonFidd1e~neck .G,C AmSluckia tassel1,ita, Cobblestone Fiddle-neck G AnagfU1is a~ensis, Pimpernel G,C,CB Arbutus menziesi;i., Madrone F Artemisiaca1ifornica, California Sagebrush C,CB Artemisia douglasii, Wormwood or Mugwort G,CB,F,W Asclepias mexicana, Mil:kweed G

Baccharis pi1u1aris ssp. consanguinea, Coyote Brush G,C,CB Baeria chrysostollla, Goldfields G Barb.a.rea orthocet:is, Winter Cress R Bow1esia incana, Bow1esia Brassica arvensis, Char10ck G Br9diaea capitata, Blue Dicks G,S Brodiaea elegans, Harvest Brodiaea G Ca1andrinia ciliata var. menziesii, Red Maids G Ca1achortus. pulchel1us, Fairy Lantern F ,W Camissonia. pvata; Sun'Cups G Capse11a Bursa-pastoris, Shepherd's Purse G Car.damine oligosperma, Rock Cress C,CB,F,W Carduus pycnocepha1is, Italian Thistle G,W,S Castilleja affinis, Indian Paint Brush G,C Castilleja fo1io10sa, Hairy Paint Brush Ceanothus cttneatus, Buck Brush C 'Centaurea calcitripa, Purple Star Thistle G Centaurea solstitialis, Yellow Star Thistle G Cerastium viscosum, Mouse~ear Chickweed F,W,S Cercocarpus betuloides, Mountain Mahogany C Ch10rogalum pomeridianum, Soap Root .G,C,CB,S Cirsium vulgare, Bull Thistle G,CB Clarkia unguiculata,Farewell to Spring G Clematis ligusticifolia, Western Virgin's Bower W,$ Co11insia heterophy11a, Chinese Houses W C011insia sparsif1ora, Few-flowered Co11insia W

46 A FLORA OF BRIONES

Genus species, Common Name Habitat

Conium maculatum, Spotted Hemlock G Convolvulus subacaulis, Hill Morning-glory G Comus occidentalis, Creek Dogwood R Corylus cornuta var. californica, Hazelnut F,W Cynara cardunculus, Wild Artichoke G Cynoglossum grande~ Hound's Tongue F,W

Delphinium decorum, Blue Larkspur F,W Delphinium nudicaule, Red Larkspur F Dentaria californica, Milk Maids G,F,W,S Diplacus aurantiacus, Bush Monkey Flower C,CB Disporum hookeri, Fairy Bells F Dodecatheon hendersonii, Shooting Star G,F,W Dryopteris arguta, Wood Fern F,W

Eremocarpus seterigus, Dove Weed or Turkey Mullein .G Erodium botrys, Stork's Bill G,S Erodium cicutarium, Red-stemmed Filaree G ErodiUIll moschatum, White-stemmed Filaree G,S Eriodictyon californicum, Yerba Santa C Eriogonumnudum, Nude Buckwheat G,CB Eriophyllum confertiflorum, Golden Yarrow C,CB Erysimum capitatum, Wallflower, C,F,W Eschscholzia californica, California Poppy G,C,CB,W,S Equisetum telmateia, Scouring Rush R Evax acaulis, Dwarf Evax G

Filago californica, California Filago G Foeniculum vulgare, Sweet Fennel G,CB Fritillaria lanceolata, Checker Lily F,W

Galium aparine, Cleavers F,W Galium nuttallii, Nutt'all's Bedstraw C,CB,W Garrya elliptica, Coast Silktassel C Geranium dissectum, Cut-leaf Geranium G Geranium molle, Hairy Geranium G Gilia achilleaefolia, Blue Gilia G,C Gynphalium purpurium, Purple Cudweed G,C Grindelia camporum, Gun Plant G Grindelia hirsutula, Hairy Grindelia G Grossularia californica, Hill Gooseberry CB,W Grossularia menziesii, Canyon Gooseberry F,W

Helenium puberulUIP., Rosilla R Helianthella castanea, Diablo Sunflower F,W Hemizonia congesta var. luzulaefolia, White Tarweed G Heteromeles arbutifolia, Toyon C,CB,F,W Hesperocnide tenella, Creeping Nettle C,CB Hieracium albiflorum, Hawksweed G,CB

47 A FLORA OF BRIONES

Genus species, Common Name Habitat

Holocarpha heermannii, Heerman's Tarweed G Holodiscus discolor, Cream Bush or Ocean Spray C',CB ,F, W Hypocheoris glabra, Smooth Cat's Ears G

Juncus patens, Spreading Rush G,R Juncus xiphioides;-Iris-leaved Rush G,R

Lactuca virosa, Tall Lettuce W Lathyrus bolanderi, Bolander's Pea W Layia platyglossa, Tidy-tips G Lepidium nitidum,_ Peppergrass G Lithophragma affinis, Woodland Star F,W Lithophragma heterophylla, Hill Start G,W Lomatium dasycarpum, Lace Parsnip G,C Lomatium ~acrocarpum, Sheep Parsnip G,W Lomatium utriculatum, Bladder Parsnip G,C Lonicera hispidula var. vacillans, California Honeysuckle C,CB,F,W Lonicera ledebourii, Twin Berry W,R Lotus humistratus, Colchita G Lupinus albifroms, Silver Bush Lupine G,C,CB Lupinus bicolor, Dove Lupine G Lupinus nanus, Douglas' Annual Lupine G Lupinus pachylobus, Mt. Diablo Annual Lupine G Lupinus succulentus, Arroyo Lupine G Luzula campestris, Woodrush F,W Lythrum hyssopifolia, Loosestrife G,R

Marah fabaceus, Valley Man-root . G,C,CB, W Matricaria matricarioides, Pineapple Weed G Medicago hispida, Burr Clover G Micropus californicus, Micropus G Microseris douglasii, Douglas' Microseris G Microseris elegans, Nodding Microseris G Monardella villosa, Coyote Mint G,C,CB Montia perfoliata, Miner's Lettuce F, W, S Myrica californica, Bayberry F,R

Navarettia mellita, Roney-scented Navarretia G,CB Nemophila heterophyla, Baby White Eyes F,W Nemophila menziesii, Baby' Blue Eyes G

Orthocarpus attenuatus, Valley Tassels G Orthocarpus erianthus, Johnny Tuck G Orthocarpus purpurascens, Common Owl's Clover G Orthocarpus pusillus, Dwarf Owl's Clover G

48 A FLORA OF BRIONES

Genus species, Common Name Habitat

Osmaronia cerasiformis, Oso Berry CB,F,W Osmorhiza nuda, Sweet Cicely F;W

Pedicularis dens iflora , Indian Warrior C Pellaea andromedaefolia, Coffee Fern C,W Pellaea mucronata: Birds-foot Fern C,W Phacelia imbricata, Rock Phacelia C,W Phoradendron villosum, Mistletoe W,S Picris echioides, Bristly Ox-tongue G ·'~ Pinus radiata, Monterey Pine Pityrogramma. triangularis, Gold-back Fern C,CB,F, W - Plantago erecta, Dwarf Plantain G Plantago lanceolata, English Plantain G Plagiobothrys nothofulvus, Popcorn Flower G Platystemon californicum, Cream Cups G Plectritis ciliosa, White Plectritis W Plectritis microcera, Rosy Plectritis W Pogoyne serpylloides, Pogogyne G,CB Polyp odium californicum, California Polypody Fern W Polystichum munitum, Sword Fern C,F,W Potentilla glandulosa, Cinquefoil G Prunus demissa, Chokecherry C,W Prunus emarginata, Bittercherry, C,W Prunus subcordata, Sierra Plum C,W Psilocarpus tenellus, Slender Wooly Heads G,CB Psolalea californica, California Tea G,CB,W Ptelea crenulata, Hop Tree C,F,W Pteridium aquilinum var. pubescens; Bracken Fern G,W Pterostegia drymarioides, Pink Creeper G

Quercus agrifolia, Coast Live Oak C,F,W Quercus douglasii, Blue Oak S Quercus dumosa, Scrub' Oak C,W Quercus lobata, Valley Oak W,S Quercus moreha, Oracle Oak F Quercus wislizenii, Interior Live Oak F

Ranunculus californicus, California Buttercup G,C,CB,W,S Ranunculus hebecarpus, Downy Buttercup . Rhamnus californica, Coffeebetry C,CB,F,W Ribes malvaceum, Chaparral Currant C,W Rosa californica, California Wild Rose CB,W Rosa gymnocarpa, Wood Rose F,W Rubus parviflorus, Thimbleberry F,W Rubus vitafolius, California Blackberry CB,F,W,R Rumex acetosella, Sheep Sorrel G,R Rumex crispis, Curly Dock G,R

49 AFLORA OF .BRIONES

~~n~s.Sl?ec,ies, Common Name Hflbitat

~al1x .h:indsiana, Sandbar Willow R S~lix ~asiolepis, Arroyo Willow R' .Sal.Vi.a ~ellife.ra, Black. Sage C C,CB,F,W ~::~~:~~::~~iil~:~~~~~iesan~cle G san.te'~la cra.$'si:c~ulis ,.' Pacific' San:icle G :" $~i~taga califort1ita~··· Cal;Lfjj'rn~a Saxifrag~ F,W Satttpeja douglasii,Yerba Buena. . CB,F,W Sca.nd1~ pectin.... Veneris., Shepherd' ~ Needle G Scu.~¢J.larl,atuberosa·, .Blue.' Skull... c~p C,CB Senecio vUlgaris, .Groundsel G Sherardia arv~nsis, .Field Madder G Sl.l.¢lle gal1ica, Windmill Pink G S:11ybtnntnarianum, Milk Thistle G S!syriilchium bellum,.Blll~-eyedGrass G Sisymbr.:l.wn officinale, Het\ge MuStard G Smilacina racemPsa var ~ . amPl.exicaulis, Fat. Solomon '.s Seal F,W · SUdlaeina'stellata va:nsessilifolia, Slitn Solomon t s Seal F,W · Symphoricarposmo:flis ,Trailing Snowberry . G,CB SOlanumuinbellifebium,. Blue Witch .' '. .CB S(>.lidago cal~fot;l1ica,· GoldenRod' G ·Sonchu'8 asper, Hollow Sow Thistle G S()l1chus oleraceus, Caban So~ ThiEitle G Stacliys ri~id,a yal' • quercetorum, Hedge Nettle CB,W · Stet1:'aria niedii-a C01nmoIl Chickweed . F,W .. '. . . , ...' . Styl,.omeconheterophylla, Wind Poppy W

Tflruicum officinale, Dandelion G Thysauocarpus curvipes, Fringe-Pod .G 'J,:illaea erecta, lNarf Stonecrop G .Toxicodendron radicans ssp. d:lversilobum, Pais on, Oak C,CB,F,W,S,R; · T·rientalis latifolia" Staiflowei F,W Trillium chloropetalumni TrillitlIIl F Typhadotninguensis, Cat-tail R

Umbell:ularia.californic~, Bay Laurel CFW, . , Urtica holosericea, Creek Nettle. R

Vid.:a americana var. truncata, American Vetch G,CB,W · Vitis californica, California Grape W,R

Woodwardia fimbriata, Chain Fern R Wyethia glabra, Mule-ears G

Zygadenus fremonti, Zygadene Star G,C,CB

50 ANALYSIS/MANAGEMENT

Disturbance/Vegetation Management/Plant Removal

The adopted policies and p.rincip1es of the District Vegetation Management Manual must be followed. Minimize disturbance and removal of natural vegetation, including mowing of natural grasslands, during .~ spring and early summer to avoid disturbing nesting. Where possible, areas near creeks (within 200 feet) should be left unmowed and vegetation should be undisturbed. All planted vegetation should be ~ , indigenous to the site. Exotic annuals, shrubs and trees may be removed unless historic specimens. No off-road vehicle use, including staff and grazing tenants, should be allowed.

Wildfire/Prescribed Fire

Wildfire is a recognized necessary factor in maintaining natural vegetation. It can also be destructive. Either a "let burn" policy or "prescribed fire" can effectively meet the needs of vegetation and fire management. When safe, allow wildfire to burn west of Briones Crest· in the. east of the Park, and northeast to Lafayette Ridge in the southwest, to maintain chaparral, manzanita and savannah vegetation types and reduce wildfire fuel. Additional fuel-reduction vegetation management may be necessary on southern a:p,d eastern Park boundaries adjacent to residential areas.

Riparian

Maintain undisturbed riparian c.orridor of 50 fe'et from creek center, except for a minimal number of· creek crossings and wa1k-dn picnic tables. Where development occurs on one side of the creek, opposite side should have at least a 100-foot undeveloped corridor. Preserve the vegetation communities (gr·ass1and, brush or oak/bay woodland) within 300 feet of riparian/creek vegetation to maintain vegetation diversity for wildlife.

Lagoon/Marshes/Bogs/Springs

Vegetation at marshes; bogs and springs should be protected by enclosures against livestock, excessive human visitation, grading and filling.

51 Oak Replacement and Protection

Natural replacement of oak species (coast live, valley, blue, black and caJiYQ,n) should be maintained or encouraged by livestock enclosure. Pl~l1ting in recreation.and staging areas should include theapp'ropriate oaks at a density of about 20 'trees per acre (50 by 50 spacing). Oaks shoUld be protected against soil compaction by visitor traffic and ove£.;;:;wated.ng frem-Park irrigation.

Planting

Pl~tings should be of indigenous species consistent with the natural vegetation, slope, and aspect (ffsite native"). Density .of .. p~~nting shduld be 20 trees per acre (50 by 50 spacing) for spreading trees~ For exceptions, see the Vegetation Management Manual •. The following are sugge~ted for planting: . Sprea4ing: oaks, sycamore, black walnut, big--ieaf maple, JIladrone.; Columnar: kn.obcone .or cddlter pine.

Irrigation and Lawns

Use .of irrigation and planting of lawns are" inconsistent with maintenance of natural vegetation. Lawns should be planted only in recreation/staging units, and even there should be kept to the nlinimum necessary to serve overfl.ow picnickers.

Rare and Endangered Flora

The rare and endangered species listed by State and Federal Governments must be protected against disturbance by parkland development or everday parkland management, maintenance or operations activity. F~rther, plant species found only in small numbers in Park District lands should be similarly protected.

Fritillary (Fritillaria liliacea). This species may occur in grassland and, if present, it is probably in the Natural Environment Unit in the ,eastern Park or Crest/Lagoon Special Protection Unit. It flowers February through April.

California Helianthella (Helianthella castanea). This little sunflower Species occurs in the oak/bay woodland and 'grass communities. It flowers in May and June and occurs an the sandstone in the Upper Alhambra Creek and Grayson Creek watersheds.

Mt. Diablo Golden Globe Lily or Fairy Lanterns (Calochortus pulchellus). This beautiful wildflower occurs an bare SOils, disturbed slopes in the .oak/bay woodland, and chaparral cOUununities, and fl.owers May through June. It grows in Old Briones R.oad Wildfl.ower Special Protecti.on Unit.

52 Grazing

Livestock should be carefu11ymonit.ored and managed to insure· that unwant~d vegetCi,tion damage is avoided. Fenced enclosures s,hou1d be considered on.1y for small areas and for springs, bogs, .and perliaps some ripari.an areas. At the lagoons, .1I1OV'ing salt licks away fro;tn. water is a preferred method of discout aging livestock tra,titp1ing th.an is fenCing. The grazing activi.ty of cattle must. be. carefully monitored' on slopes. To enable resource .. managers to.. bet.ter understand. th-:i.s, Figure IV! F-2: "Grassland Management Strata", a model of slope and grassland produced.

FIGURE IV. F-2: GRASSLAND MANAGEMENT STRATA

Thi.s m.ap slJ,ows. the.~e1ationship. between slope and grassland. The potential animal units for each strata·.are given.

Acres A.ml Grass/Open Shrub 0-10% 600 840

Grass/Open Shrub 10-25% 915 840

Grass/Open Shrub 25-55% 1190 710

Grass/Open Shrub 55+% 20 o .. . CJ Forest/Woodland/Brush all 2300 575

Thistl.e and Broom Encroachment

Artichoke thistle, star thistle and broom are weeds which, respond to soil disturb.ance. Th;i,st1etendf3 to invade grassland, and broom invades barren areas, grassland or brush•. Thistle and broom should be' controlled on ridges and valleys. Hand 1al>or and, where necessary, herbicide should be used.to eliminate thistles and broom. Special rapid eradication shbu1d be undertaken in early stages of thistle invasion in new areas.

Over-browsing

Over-browsing by deer, tu1e elk, or other ungulates should be monitored and population reduction undertaken if needed.

53 '------management G. WILDLIFE/FAUNA

General .

~, ,'. ~~h: of the f01I~:ingWri.ti~·i~·· ta:~' frd~;" ~ comprehensi~~ "Wildlife ~$eme~t; .. Plan 1=Qr Bl::.*9lles~g·~Ol'la~.}?ark p~~pared~" ~(!ott: Min:~1;"...... 'U~~'\t~rsir~y

T4~ .~i.gh: :;~i;vErtsi ty an(t<;legre~. of i.D,tersper;~i.(Jn. qf ve,getB;tion types, 1~!,~ ~M#F of }?~en .~?~.~e'¥f avai1f3.bUi~f}i)f v~~~r t4~~pg~out.}he year, ;tn Brion~s .~gional~a1jk. creE1tea.ve~ productive hab;ltatf9l: ..ife~ The 'fo+lowlpg.,est~ate~ of ,th,e P()~l~ti(Jns ancl.di~tributiotis . of;':, ~ s~ ..;}dl4li(.e sR:~e;les '~Q~.f3idere,~':in ',fII~~~gement:~phlna~e bas~d olitne hi;lblitatllibdels wnich' ~re' attaelled~p~a:£~es. '.' .. '

~b,~at ;~dels Jlav:e.·1>e~n/.dev~19ped .~or,ea~1l::.I'~~ tb,,;~.iJt .i;e:~~cted:·,spe~ie~· .. " 'i#<'~d:el'::;~~ es~J.~te t,lJ;eir pi'~ent~kll,Jl4Stl.Si~{~~~~~~~ttibtiti~on 4ll:~: to'.,'; , de·~ei:lidn~factots which may be l~ting .t4e:i~, 'P9PijJ.at';iolls . in di.ff~rent· 'P~~J;$ 'of, .. thepark.Ba$e~ on .~p, inven1:oryatid~f¥;;is(#~xistlng' . ' .. cOnt\itio;rts.itithepark;a. wildl4fe ma:nagem~n,t pl.;.nhas,b.,~n deiTelopedtp acn1tivet:he. st~t~d wildli.fe manag~eht goal~~.·.' .' ". .' .' '. 'Theha~itat mode,;ls wer~.;de'VelQB'~d through .~·l:ev:le*·~:g.d s~thesis.of sc':l.eiltific ·literatureaild consultationwitb 10cal;,e~erf's~! The di~tributiQn ~lld .ab'l,1ndan~e 'of the silt select~~ sp~~ies1" ~spredi.ctedby thehabit~t: modets, areilll,lstl;ated on uulll$·.aira.ilable ·atpistri.ct H~~~~uart~fs labeled w:i:ththE{lt~es<:of·'·~hclspecies:and ~li~word:' Itpt;esent It, ~ • . ". "

",; c )' ':'{, w1ld1.ife :SRecies Considered and' Specific Goals

. l'hew~ldlife pl~n:cpn.~id~rs.s;~ species whiih have been sele'cted for detailed inVestigation based upon the uniqueness or rarity of the .. specie~, and'th~ val\l~. oft\1~ I?pecf'?s as. ip.dicators of . the quality.ari<,f "'diversit:y of· overa~l;.:·wildl'iFe .hab:i,i:at.-r,lle species 'considered, teasqns fO,r, their selection,.··· and specific management goals are: .

. Columbian black~talJ,.ed deer Od,cic.pil,eushemionu.s columbianus. Deer a¥,e the6nly' native ungulates in the. park and havj:l t.pe P9t.entia~ .t.o sev;el::ely degrade vegetation in the'park if 1:;heir population e~ceedsthe park's carryip.g ca:p,acity for dee.r. . .Deei~prov:Lde a food sou:rce for ijome

54 carnivores, particularly mountain lions, and are comparatively visible and interesting to park users. The specific management goal for deer is to prevent the degradation of park vegetation by excessively high numbers of deer.

The park currently supports about 190 Columbian black-tailed deer during the summer, which is when forage is least available. The park herd is estimated to consist of about 33 bucks, 13 yearling males, 20 yearling females, 65 does~.~nd 65 fawns. The proportion of bucks is relatively high compared to most deer herds because of the exclusion of hunting from the park. Deer OCCUT in the greatest densities in the northern, eastern, and southern portions of the park, while densities are relatively low in the western and central areas where there are extensive grasslands. During the summer, the absence of brush for browse is the major factor limiting the distribution of deer.

Gray fox Urocyon cinereoargenteus. Gray fox are relatively abundant in the park, but are currently competing with feral cats for food resources. Gray fox are an indicator of the quality of habitat for other mammalian carnivores with which their food habits overlap •. The specific management goal for gray fox is to increase their population within the park. It is estimated that the park presently supports about six gray fox, which are most likely aggregated into two family groups located in the eastern and southern parts of the park where there is the greatest amount of brushland and woodland. Prey density and the availability of suitable vegetation types are probably the most limiting factors for gray fox.

White-tailed kite Elanus leucurus. Kites are considered a depleted species and are an indicator of the quality of habitat for other rap tors with similar food habits. Kites are comparatively visible to park users and are of high interest to the public because of their relative scarcity. The specific management goal for white-tailed kites is to increase the nesting population in the park. A single pair oC white-tailed kites has nested near the lagoons on Briones Crest. The kite population of the park is limited by a loW' density of its primary prey species, the California vole Microtus californicus, due to grazing. Voles require about a one-year accumulation of grass mulch in order to reach the high densities required to support nesting white-tailed kites. In grazed areas, sufficient vole densities to support nesting kites only occur near marshy areas, such as the lagoons in Briones.

California quail Lophortyx californicus. Quail are a good indicator of habitat qua1:l-ty for a number of other species with similar food, cover, and water requirements. The specific management goal for California quail is to increase their population and distribution within the park. California quail are estimated to be very abundant in the park due to the high degree of interspersion of brushlands, woodlands, and grasslands in the park, in addition to the favorable distribution of water sources. Quail densities are greatest in the northern, eastern, and southern portions of the park where there is the greatest amount of brush and woodland cover. Lack of cover excludes quail from much of the central portion of the park, while lack of water is the limiting factor

55 in portions of the park near the southeastern and northeastern corners and along portions of the western and eastern boundaries•. The present population of nesting quail in the park is estimated at 680 pairs.

California tiger salamander Ambystomatigrinum californiense.

The tiger salamander is a relatively scarce amphibian which is considered to be a "vulnerable species" by the International Union for the Conservatiou__ Q.f Nature and Natural Resources •. Tiger salaI!landers have some value as an indicator of the quality of habitat for other • L", amphibians.. The specific management goal. for tiger salamanders is to increase their population and distribution within the park.

The California tiger salamander presently occurs in about 96 acres of . grassland and woodlap.d surrounding the four lagoons on Briones Crest. Abundance of tiger sa.lamanders cannot be estimated due to the lack of reported research on the subject. It is considered likely tl1.a.tthe tiger salamande:rpopulation could be low when compared to capacity. Cattle disturbance or lack of terrestrial cover. in the grasslands surrounding the lagoons is considered a probable cause.

Alameda striped racer Masticophis.lateraliseuryxanthus. The striped racer is one of the rarest snakes in the East Bay and has been designateda "rare spec:i.es"by the Depa.rtment ofFish and Game. Its distribution is limi.tedtoAlatneda an,d Contra Costa Counties. Most of the striped racer's remaining habitat is on .EBRPDand East Bay Municipal Utilities District lands. The specific management goal for. the striped racer is to increaseitspoplllatioIlwithin the Park. Alameda striped racers are expected to presently occur in about 300 acres of brushland and adjacent grasslandandwoodlandin.thesouthern andea.sternpbrtions of the park. No information on which estimates of the density of striped racers can be ba~ed is available •. However, the number of striped racers in the Park is probably limite

Fauna

The following survey assesses free-living vertebrate an:i,mal speci~s and . identifies use by major habitats in Briones. Its purpose is to provide information whIch maybe useful to the development of management policies for the Parks . . The method is adapted from a studydoD..eior the Park District by Robert C. Stebbins, August 11, . 1975, "Use of Habitats in the East Bay Regional Parks byFree~livingVertebrate AnimaJ..sl' • (Mr. Stebbins study can be found in the District's Vegetation Management Manual). The list of species Mr. Stebbins established has been edited by additions and deletions.

56 A judgment was made for each species as to the extent of its use of the habitat in question. Use categories were: a = "rare or absent"; s = "slight"; m = "moderate"; f = "frequent"; and r = "resident". 1 A few generalizations about wildlife habitat value can be made. Habitats are listed below roughly in the order of habitat richness as reflected by numbers of species:

(1) Grassland, the most abundant Briones habitat, is less rich in species and "attractiveness" than the other native habitats. Grassland , .,. is generally used by seed and insect eating birds, ground burrowing rodents and snakes, and birds and mammals of prey. Gras.sland in flat terraces near streams is richer in habitat value because of "edge effect", availability of water and nesting sites, and high soil moisture levels which results in longer growing season for vegetation yi~lding more seed and wildlife food.

(2) Oak-bay-buckeye woodland and savannah is abundant in Briones and richer than grassland in species because of the presence of the trees which provides additional types of food (e.g. acorns) and nesting sites.

(3) Coastal brush may be more or less rich depending on the plant species present. Simple coyote brush stands are less rich than if poison oak, sticky monkey flower, and sagebrush are present. Very moist coastal brush (sometimes called moist chaparral) is rich habitat because of the abundance of fruits available for wildlife (poison oak, gooseberry, elderberry, etc.) and its moist site characteristics.

(4) Dry chaparral (chamise, toyon, black sage) adds wildlife diversity to Briones because it is dry, generally rocky, and provides habitat for animals not found in parklands near the Bay.

(5) Mixed hardwood (broadleaf evergreen) forest is very rich wildlife habitat because of the great diversity of tree and shrub species. It generally contains the species of the oak-bay-buckeye woodland and of the moist chaparral plant communities in the canopy and understory, plus additional plant species yielding a greater variety of habitat potentials than either one.

(6) Riparian forest is the rarest and richest wildlife habitat, in that it provides a water source, productive food sources (e.g. willow), cover (or shelter), nesting sites, "ecological edge", and animal traffic corridors. It is recognized as containing the most animal species of 'any plant community (vegetation type).

It is probably safe to assume that the invertebrate fauna follows similar patterns of diversity. Many of the vertebrates depend directly on invertebrates (insects, spiders, mollusks, etc.) for food and thus vertebrate diversity and abundance may be indicative of the richness of 'the invertebrate fauna. The vertebrate diversity probably also reflects plant diversity.

5J The following table identifies vertabrate animals found in Briones and gives the expected habitat use for each. The habitats are:

Gr.assland = G Chaparral = C Coastal Brush = CB Oak Savannah = S r Oak Woodland = W Mixed~Hardwood/Riparian Forest = F Pond = P

The following is a summary of the total habitat use for:

Seecies G C CB S W F P

..... Birds: 129 75 78 97 100 93 88 56 Mammals: 33 26 28 22 31 19 17 10 Reptiles: 15 15 15 15 15 15 12 6 Amphibians: 9 7 7 7 6 9 8 7 Fish 2 2 G C CB S W F P BIRDS - continued

Acorn Woodpecker a a a r m s a Ash-throated Flycatcher a s m f f s m Black Phoebe m f m s s f f Say Phoebe f f s s a r a Western Flycatcher a s m m f m s Western Wood Pewee_ a s m m f m s Olive-sided Flycatcher a s m m f m s Western Kingbird f m m m a a m Horned Lark r f a m a a a Violet-green Swallow m s m s f s f Rough-winged Swallow m m m s m a f Barn Swallow f m m s m a f Cliff Swallow m m m s f s f Steller Jay a a s a f f a Scrub Jay m f r f f s s Chestnut-backed Chickadee a a m f f f a Plain Titmouse a m m f r f a Bushtit a m r f r f a Red-breasted Nuthatch a a a s s s a White=breasted Nuthatch a s s m f f a Brown Creeper a a a m a m a Wrentit a f r a s 5 a House Wren a s r s f s a Winter Wren a a m s m f a Bewick's Wren a m r f f s a Mockingbird a s m m f a a California Thrasher a r r a m a a Robin s m f m f s a Varied Thrush a s m s f f a Hermit Thrush s s m m f f a Swainson's Thrush a a f m f f -- a Western Bluebird f m s f m a s Blue-gray Gnatcatcher a m m m m s s Golden-crowned Kinglet a s s s m a a Ruby-crowned Kinglet a s m m f s a Water Pipit m m s a a a a Cedar Waxwing a a m m f m a Loggerhead Shrike f f m f s a a Starling s m m m m s a Hutton Vireo a a m f f f a Solitary Vireo a a s m f f a Warbling Vireo a a s m f f a Orange-crowned Warbler a s m f f m a Nashville Warbler a a s m m m a Yellow Warbler a a m m f f a Myrtle Warbler a s m m f f a Audubon Warbler a s m m f f a Black-throat Gray Warbler a a m m m m a Townsend's Warbler a a m s m f a Hermit Warbler a a m m m f a

59 G C CB S W F P BIlIDS - continued '.

~t.q;Ulivray Warbler ':8,' s m s m m a ~. W11~on W~bler a a m m m f a H~u.s~" Sparrow: s a a a a a. a Wes:t;~rn· 'Meadowlark r m a m a a a R~d~Wiiiged .Bl:ackb.i~d m s s .111 s s f "::' .' ..... " .. '. .Bullock s Oriole a a s m III m a .. B~e«e:r's'Bl~c;kbir4 f f III m S m f ."" Br()lfu:..headedCowbird s 8 m 111 m .. ~ m We~.t:ern.Ta~a'ger . a a 8 S f a a iUac:k .... beaded Grosbeak a a m s f ·f a .~; L.dUi;i: ~1:tUting m m 8 f . 8 8 a Puq,le Finch . a a S. 8 f a a Hoq,~e Firieh . m m m m f s a . Pine. Si:skin a 8 S m m s a ~ricanGoldfinch 1D. m m m m m a ies~er Goldf:lnch . f f m f 8 m a t,i~e~ce'Goldfinc1;l m f f m s S a Rufous-sided Towhee a m r s f m a ;Brawj:t ToWhee m r m s m m. lit Saya:pnah. Sparrow r f a. 111 a. .a a GX:-2l;ishopper Sparrow r f a m a a a Lark Sparrow·· f f a r 2. $ a au~ous-c;owned Sparrow a m a a a a a Slate-colored.: Junco a 8 8 m m m a Oregan Junco·.. 8 f f m. f f'" a Chipping Sparrow a a a ni m 8 a White.... cli'owned Sparrow. m f m .8 8 m a Gol.den-crowed Sparrow f f m 8 8 m a Fox .Sparrow s m f 8 m Ill- a. Lincoln SparroW. a a 8 S. s .8 a Sat;lg SParrow a m f 8 f f a , Vesper Sparrow f 8 8 m a a a Pied-billed Grebe f Cat;ladaGoose f Wili,te:"f:z;:onted Goose f Snow. Go08e f Mal1ard~; r Pintail f . American Widgeon f Gadwall f Shoveler f Le8ser Scaup f Bufflehead f Common Egret f Snowy Egret f Great Blue Heron f Green Heron f American Coot f Killdeer f

60 G C CB S W F P MAMMALS

Opossum m m m m f m m Bro4d-footed Mole f f m m m m a Trowbridge .. Shrew s m f m m S a Onate Shrew f s s s s a a Raccoon s s m m I'll f m L09g-tailed Wease~_ m m a m s s s Sp

Feral Cat s m m s m m a . Domest.ic Dog m a a , a a a a Cattle f s s f a a f

REPTILES

Western Fence Lizard f f s m m a a .Northern Alligator Lizard s m f s f s a Southern Alligator Lizard f f m m f S a WesternSkink f f s m f s a Rubber BO.a s s f s f m a West. Aquatic Garter Snake m ni m s f f f West. Terrestrial .G. Snake f m m m f f m Ringneck Snake m s f m f s a Sharp-tailed Snake f m m m f s a Racer r m s f s a s Striped Racer f f .. B m s m a

61 G C CB S W F P

Gopb,er Snake r f m f m m a .Co1lUl:lOJ1 Kingsriake f f s f m m S W'estern ;Slack-headed Snake f f s m s a s Westt~~ Rattlesnake f f s f m m s

..AJnllt '/'nIANS .. . ' ...... :: Ca.lifornia Newt -,- m s m m f f f '''\ Ro~ah~s~d.nned .Newt m s m m f f f Calli., .Slender Sa1B.11lander lIi s m m f s a E'Ilsat;ina a a m a f s s m f .~ Arboreal, .". Salamander m s m s s Wes~~;n '.&oad ., m m a m s f m Pacific Tree£~og f m 111 m m f f Fo.othill Yellow-legged Fr. a a a a m a a Red~le~ged Frog m s s a f m r '. FISII ~ MoSq'\1l:to.Fish r Gold Fish r

ANA4YSIS!MANAGEMENT

Wildlife Ma.lia,gement Goals and Constraints'

Bas.eA. on the ;EBRPll Master Plan and. on consult,ataonwit,hJi;BEPD personnel, the goal of wildlife management in Briones. Regional pa.rk. is to maximize the diversity and abundance of.na:tive wildlife with special attention to unique or rare species. 'Wildlife management activities should not impair the na.turalness of the park 's appearance andshou;Ld be. accomplished with 1I!i'Il1mum alteration, of natural .biotic c6immiriities. Limitatipns pn publicrec.reation are incompatible with.tp.e p:t.'imary purposes. ·of the. park and should. be avoided... Livestock grazing on ·parklands is recognized as an impcirtatltseurce, of f1ltlds for operation of the park and as an effective means of vegetation management. However, the adverse impacts of livestock grazing upon the primary purposes of . the park, including the preservation of wildlife habitat, should be minimized.

62 Wildlife Management Guidelines

The proposed W'ildlife plan .recommends a high degree of management of livestock in the 135-acre area of grassland surrounding the four lagoons on Briopes Crest in ord~r to enhance hab;i.tat forthewhit:e-tailed kite, the California tiger s.alamander, and related raptor and amphibian sp,et::,ies.The ~ldlife plall proposes the enhancement of ;'1egetatj,ve wildlife cover at the lagoons and development of water sources .' (ilfstallation of -spring .boxes or water troughs) in several.areas on the . .., ~riones Crest and along Alhambra Creek to eliminate existing deficiencies These areas b,avebeen identified 'as the most' diverse wildlife areas of the park. This planting of native brush and tree ~ , specie::; (e.g. willow) near the lagoons would il1creas~ the availability of water to wildlife' species which require nearby Cover.

Rc,.t::ational 'presc.ribedburning pf desigriClted bru~h1ands (about 40 acres) in the .souther!): and, eastern portions of the park is,reco~en4ed on a 20-year rotation to enhance wildlife habitat. ThiS would also reduce fire hazard and maintain th~ natural c()mposition of the vegetati~n in the designated areas." .

Direct management of Wildlife propo~ed by the plan 1,ncludes the trapping and removal. of feral cats, elimination of dOmestic dog packs., the introduction of California tiger salamanders inCo Hirschkind Pond where they do not present.ly occur, monitoring of the parkts deer population, ground ,squirrel control if necessary , and consideration of .. reintroduction of two endangered species, the San Francisco Garter Snake and the Tule Elk to the Park. .

The pl~n proposes the distribt,ltlon of a .natural history .. broc1ture to enhance public enjoyment of wildlife in the park and to discourage the removal or disturbance of wild animals.· 'A program to monitor and map wildlife in the park in cooperation with b.culty and students of local colleges or Universities is also proposed , possibly using the East Bay Regional Information System (EBRIS) to store maps of species sitings.

The effectiveness of the full proposed plan as recommended by Mr. Miner has been projected by applying .the habitat:modeis for the six Selected species to the habitat cond.itions which will exist in· the park following implementation of the p.lan. White-tailed ki.te and california quail populations in the park are expected to increase by up to 300% and 16%, respectively. The gray fox population is expected to increase by at least 17%. California tiger salamander and Alameda striped racer populations will also. increase substantially, while deer depredation of Park landscape vegetation wil~ be significantly reduced.

63 H. RANGE

INVEN'.I:ORY

'. '"'4. Brion.es has been grazed since the Spanish came to the area in the early 1800's. It represents a significant agricultural resource in Contra Costa County because of its range capability. District staff has estimated that Briones has over 3,000 animal unit months (AUM) of grazing capacity. (One AUM is the equivalent of a full grown cow or bul19f 800+ pounds on the range for one month.) Grazing potential is primarily located in areas of grassland, open shrub/grassland, and savannah within the park. Figure IV. H-1: "Range Capability" depicts the distribution of this grazing potential through the park. Range is used by both domestic livestock and wildH.fe, and use must theref0re be rationed between the two. To some extent different species graze on different plants which permits partial to complete coexistence of species in· the same area. ..

The following table indicates the trade-off ratios for different animal species.

TABLE IV. H-1: RANGE USE COMPARISON RATIOS

Weight Species (lbs. ) Ratio

Cattle,. Horse 1,000 1.0 Elk 600 1.5 Mule Deer 150 4.0 Pronghorn Antelope 100 6.0 Black-tailed Jackrabbit 5 50.0

Source: Heady, Harold F., 1975, Rangeland Management, p. 149.

FIGURE IV. H-1: RANGE CAPABILITY

This map shows range capability in animal unit months per acre as attributed to different soil series by the U. S. Soil Conservation Service in the Contra Costa County Soil Sur~ey. D 0-1 [::::::)1-2

. lEmma...... 2-3..---- 3+

64 ~. BRIONES REGIONAL PARK . range ---- _.. . - - CONTOUR INTERVAL 80 FEET capability The Park is grazed at an authorized level of approximately 2,500 animal-unit months (AUM) of utilization. This is somewhat below the capacity of the range.

Cattle distribution is a problem due to variability in water supply, so that certain areas of the park tend to receive a greater amourit of grazing pressure than other areas, notably on the slopes above Bear Creek Valley. Fencing, water developments, and timing of grazing use can be employed as means of dealing with the distribution problems.

Fencing

Fencing within the regional parks is done primarily for four reasons. These are 1) property line fencing, which serves to delineate property lines and reduce problems of trespass in either direction; 2) pasture fencing, which is interior fencing to effect better distribution of livestock use; 3) wing fencing, which service to funnel or otherwise direct livestock movements during gathering or release operations; and 4) exclosure fencing which serves to restrict or prevent access by livestock to areas where they are not wanted. Existing fences are shown in Figure V. A-I: "Improvements".

Water Development

Briones Regional Park has a number of natural water sources including several natural lagoons, creeks, and spring or seep areas. .' In addition there have been a number of impoundments constructed throughout the park to retain winter storm runoff and further supply water for livestock and wildlife. A problem with grazing by livestock has been the damage, particularly to the smaller ponds, springs and seeps, caused by the trampling effects of , these large animals.

Pest Control

There are three species of plants which have been of particular concern as pest species within the park. These are the yellow star thistle, purple star thistle, and artichoke thistle. Of these the yellow star thistle is the most widespread, least amenable to control, and of the highest value as a forage resource. The purple star thistle and artichoke thistle are both highly undesirable species of low forage value, serious threat to adjacent private agricultural lands, and of major detriment to recreational values.

The only animal species of serious concern as a pest is the Beechey ground squirrel. This native rodent is a prolific breeder and is felt

65 by the agricultural community to cause serious problems of erosion, damage to crops, and serve as a reservoir of diseases, many communicable to man.

ANALYSIS /MANAGEMENT

Fencing . "" District plans call for the realignment of pasture fencing in certain areas of the park to effect easier maintenance vehicle access (i.e., eliminate unnecessary gates) and reduce visibility of fencing on ridgelines or other prominent features. Exclosure fencing is planned for water sources as described below.

Water Development

District plans call for the continued maintenance of existing water sources and their enhancement through the construction of exclosure fencing and provision of water to nearby troughs. This is expected to impt'ove both water quality in those areas and cover for wildlife.

Wildlife Range Use

The District plans to adjust grazing allowances to insure that the range resource can support wildlife to a high level.

Reintroduction of Tule Elk

Reintroducing tule elk to Briones would be significant change to the area. The large ungulates eat almost as much as cattle and are difficult to keep contained. The District should work closely with the California Department of Fish and Game, and adjacent landowners such as East Bay MUD to investigate the possibility. One major problem is that until the State tule elk population reaches 2000 individuals, the State allows no population control (deprevation) of the animal. Neighbors of Briones may take exception to the tule elk if released. Only an extremely high and expensive fence could keep them contained. Briones Park, East Bay MUD watershed land, and Tilden/Wildcat Parks together comprise a large potential habitat for the Elk. The staff recommends reintroduction when the legal barriers are eliminated and a deprevation policy change occurs.

66 Pest Control

District plans call for the control of both purple star thistle and artichoke thistle through mechanical and hand removal, burning, and chemical treatment in order to reduce the populations of these species to tolerable levels. Because of the tremendous populations of yellow star thistle, no __lormal programs are contemplated at this time. The Beechey ground squirrel occurs in Briones Park in small numbers and is not considered a threat to grazing potential or to neighboring properties. Dynamics of the population within the park will be monitored and control measures taken in accordance with overall District policy regarding control of this species.

I. WILDFIRE

INVENTORY

Briones because of its natural vegetation is subject to wildfires. Wildfires have had a role in creating the present vegetation patterns. Wildfire suppression has led to vegetative fuel accumulation. Steep topography can restrict access for firefighting. Fires also tend to burn upslope and are more intense the steeper the slope. The fire season generally runs from late April to early December. The prevailing wind direction is from the west. Extreme fire conditions can exist during the fall after annual vegetation has dried and when strong, dry northeast winds are blowing. The principle locations of residential areas which could be threatened by wildfire are located south,north, and east of the Park.

Using EBRIS data files, the District staff has modeled the potential wildfire terrain-fuel conditions for the area of Briones. This modeling uses the equation IP = V x S x A, where IP is WILDFIRE INTENSITY POTENTIAL. Y is the vegetation type from 1976 Landsat modeled for moist and dry forest types. These vegetation types are derived from the CDF Landstat classification with designation of moist hardwood forest/brush based on slope and aspect. S is slope derived from Digital Terrain Tapes (DTT--U. S. Army). The four slope classes follow the first four slope classes of the National Fire Danger Rating System of 1978. A is Aspect derived from Digital Terrain Tapes (DTT) and values were assigned based on wind direction for west and northeast wind conditions.

67 West Wind--Moist Air Value Northeast Wind--Dry Air Value

Aspects Aspects

N. S. SW, W, NW 2 SE, E, NE, N, NW 3 NE, SE, E, Flat 1 W, SW, S, Flat 2

Vegetation Vegetation

Brush (Coyot~-Brush) 10 Same values Hardwood/Brush 7 Conifer, Conifer/Brush Conifer/Hardwood 6 Hardwood, Hardwood/Con- ifer, Eucalyptus 5 EBRIS Mixed Hardwood, Hardwood/Brush (moist aspect), Eucalyptus 4 Grass, Open Shrub 2 Urban Open Space, Agriculture 1 Water 0 Barren 0

Slope Slope

56% 10 Same Values 25-55% 7 11-25% 5 0-10% 2

Intentsity Potential Class (A x S x V)

Extreme: 84+ Same Values

High: 20-83

Moderate: 10 .... 19

Low: 0-9 • Urban N/A FIGURE IV. G-l: WILDFIRE-WEST WIND and FIGURE IV. G-2: iHLDFIRE-NORTHEAST WIND show the areas of extreme intensity (darkest) grading to low intensity (lightest). Intensity potential is the expected heat and flame height at a particular site should a wildfire ignite vegetation (fuel) there. Intensity increases with slope steepness, increased burnable fuel quantity, dry exposure, and aspects facing oncoming wind.

68 .. ~ BRIONE~REGIONA~ PAHK WllaTlre -:--... -:--- !!Sao _ t.~' - CONTOUR INTERVAL 80 FEET -gpu _ I west wind ~ BRIONE~_~~(:iIUNAL ~:'~I\; WIIOTlre

CONTOUR INTERVAL 80 FEET I northeast wind ANALYSIS/MANAGEMENT

General Fire Prevention

Wildfire is a necessary part of the natural environment of Briones as is . evidenced by the __ ~daptive features of plants to fire. This means that complete exclusion of wildfire from Briones is not necessary and if . '~ practiced as the resource management would lead to significant impacts on native vegetation. Complete suppression of wildfire also may lead to excessive vegetative fuel accumulations.

A good up-to-date inventory of vegetative-fuels should be maintained for Briones. Input to the EBRIS data base, this can be combined with USGS Digital Eleyation Models to determine and to map wildfire intensity potential (fuel hazard conditions). If a fire spread model is developed for the East Bay, the data could be used to project fire spread patterns and possibly rates of spread to residential areas from different. points. Mapping of fires on USGS 7!.z-minute quad maps is required as part of this Plan and should be done by the District Fire Department. Date and reason for fires (arson, natural, accident) should accompany the maps. Fuel stick and spot weather measurements should be recorded by the Fire Department once each month to establish annual fluctuations.

Man-made fire by arson at Briones has been infrequent to date possibly because of the minimal access available at Briones. Control of access by gates, and carefully planned location of trails/roads and recreational facilities, are important for control of arson. Picnic areas and public roads, if possible, should not be located at the bottom of a steep slope covered by chaparral. Adequate fire breaks should be built around all facilities •. (See Wildland Fuel Management: Guidelines for the California State Park System, 1976, California Department of Parks & Recreation).

Fire Trails

Briones has a well developed fire trail system to provide access to the various areas of the Park. The steep slopes make access difficult without fire trails; someplaces even bulldozers cannot go safely. Fire trails on steep slopes will tend to fail if left unmaintained. Consequently, fire trail maintenance is the principle resource management requirement for fire protection.

Fuel Breaks

A fuel break zone of varying Yiidth (100-300 feet) on which the density of vegetation (fuel) has been substantially reduced to permit safe

69 access for fire fighters. Generally, the central zone of the fuel break would be a bare earth road; although a gentle terrain that may not be necessary. In any event, the vegetation at the center of the fuel break would normally be grasses and other low growing plants with density of shrubs and/or trees gradually increasing toward the edges. The major place where fuel break conditions should be maintained runs along the Briones Crest east and south along Lafayette Ridge. Vegetation in this area is such that little or no alteration is needed. (WiJ,dland Fuel Ma.nagement, 1976).

Grazing

As it is District policy to retain grazing for purposes of fire hazard reduction, vegetation management, and income production, the parkland has been retained in grazing by cattle and ~orses.

Wildfire/Prescribed Fire

Wildfire is a recognized necessary factor in maintaining natural vegetation. It can also be destructive. Either a "let burn" policy or "prescribed fire" can effectively meet the needs of veget<;ition and fire management. When safe, allow wildfire to burn west of Briones Crest in the east of the Park, and northeast to Lafayette Ridge in the sQuthwest, to maintain chaparral, manzanita and savannah vegetat;on types and reduce wildfire fuel. Additional fuel-reduction vegetation management may be necessary on southern and eastern Park boundaries adjacent to residential areas.

J. VIEWS

INVENTORY

The natural appearance and open space of the gentle valleys, the broad crest, the narrow ridges and the steep slopes are great visual resources "for Park users and surrounding communities. As seen in Figure I. E-l: "Major Features/Park Names", Briones, Mott, and Russell Peaks and Bear Creek and Alhambra Creek Valleys are especially notable visual resources.

The topography of Briones provides open space views from surrounding communities, a rich variety of views from Park peaks, and many enclosed spaces in Park valleys between ridges. Bear Creek Valley, Homestead Valley, Toyon Canyon, Fallen Leaf Canyon, and Alhambra Creek Valley are isolated from recreation development at the present time. Existing

70 structures on Park ridges are a brick communications building and tower on Miwok Peak and a residence on the ridge near Old Briones Road parking lot.

ANALYSIS/MANAGEMENT

Two types of view~ are experienced in Briones~ those completely internal to the Park and others external to (looking out of) the Park. The '~ internal views are entirely under the control of the Park District. External views are controlled by adjacent landowners. Internal views should be protected against unsightly grading or development. Access for visitors to ext~rnal viewpoints should be provided by trails. Special use trails enabling Park visitors to attain views of natural resources or unique Park features should be provided. An example of this is the existing road to Homestead Valley, which provides birdwatchers an elevated viewpoint in the forest canopy.

No additional structures should be built on ridges or slopes to protect views from surrounding communities and inside the Park. Park facilities such as parking lots, should be located in'areas that are visually screened from natural areas in the Park, if possible.

K. ARCHAEOLOGY /HISTORY

INVENTORY

Archaeology

The District requested the Northwest Regional ·Office of the California Archaeological Site Survey to conduct a literature search for Briones. According to a letter of May 25, 1981, the Park contains no known archaeologic sites but does appear to have a moderate to high probability of containing pre-historic hunting and food gathering sites (Northwestern Archaeological Clearinghouse, 1981). Sensitive archa~ological areas are probable at Alhambra Creek Valley, Sindicich 'Lagoons, ,Bear Creek Recreation Un.it, and along all creeks as shown in Figure IV. K-1: "Archaeology".

FIGURE, IV. K-1 : ARCHAEOLOGY

Shaded areas on this map show areas of archaeological sensitivity.

71 .. ~~ BRIONES REGIONAL ~~.Ht\· arcnaeOiogy CONTOUR INTERVAL 80 FEET I The original inhabitants of the East Bay were Native Americans called CostallOans (coast dwellers) by the Spaniards. There· are no mounds or middens which identify Ameri.can Indian settlement known to be inside Briones Park. The Miwoktribeis also knoWn to have hunted here.

History

-':"~ MosLef the Park was .once part of Ranc::ho Boca de la Canada del Pinole . ... (ranche at the mouth 6f Pinole Canyon); pupularlyknewn as Ranche San Felipe. In 1829 Felipe Brienes b~nta heme near what i$new. the Bear Creek entrance .of the park,culti:trated surroundi.ri,g -land and raised ~ - cattle. ~riones was killed in 184Q, and in 1842 his widow,Maria Manuela Valencia Briones, petitiened Governor Alvarado for a grant tethe land the family had occupied. Thegrant,'cevering, theee square leagues, was issued on,June 1, 1842~' ,

After California became a state,the title was centesteCl, but Senera ~riolles I title was upheld by the :U.'S!D:l.strict Courtirt1860. At-that tiIne ~ .much ,.of the ranche waspu]:"c.hased by ~~mon and EI:Las Bl\itll.' Challenges to the boundary· surveycqntinued .fer nmny yeats, and it was 'notufttil 1878 that a patent to the 13~316.26acre rancho was issued .. , '. . . . ' ; " '," -" " , '. .,

'In additi.on t6 Rancho San Felipe, the Fark i.ricludes· small portiens .of R~p.che Canada del Hambre y.l~$B(nsas~ and Rancho Acalanes.

lrithe·1850's and 1860's the Alhci,tnbra Valley (renamed from Arroyo del lrilmbJ;:"e) was develoj)ed into rich:orchards a,tid vineyards. It became the coUnty:'.smost important fruit growing area •. The remains of many .of these' oldorcharcls are still noticeable.

Cattle grazing has been th.e major land use in Bear Creek watershed and the ridges since the Btiones firstsettl¢d there.llayand grain, as, well as unitrigated truck crops, have .beenpfodticed in the valleys interIilittently for some, years ~ >,

The Alhambra Water Tunnel was dug in part at a spring in'the 1860's ill a hill at the he.adwaters o.fAlhambra Creek~ It penetrated horizontally 200 feet irt the expectation that it cou,ld furnish water for the City of Martinez,. It did not work out as 'the. supply was not consistent.

Over 70 years ago a Mr. Griffin went up to the same location and enhanced the digging of the spring by several hundred feet. The water is now piped to serve the Griffin, Santos, Vierra, Robiecht and Griffiths families. The locked gate to the tunnel is now visible to hikers.

Ownership patterns reflected the land uses. The land was-divided into numerous small parcels in the rich agricultural Alhambra Valley area, while most of the land of Bear Creek watershed was in large ownerships.

72 In 1880, moved to Martinez after marrying Miss Louise (Louie) Strentzel. Here he hiked the hills during his times at the ranch when home from his Sierra trips. The following are two quotes; the first is written by his mother-in-law, Mrs. Strentzel, and the second by him:

"Louie went with Mr. and Mrs. H and their daughter to the Briones Falls. Took a nice lunch with them, gathered a quantity of f~rns, and returned by Lafayette and Walnut Creek,lI

Diary of Louisana Strentzel, July 1, 1878.

"Another lovely day, mostly solid sunshine. Took a fine fragrant walk up the West Hills with Wanda and Helen, who I am glad to see love walking, flowers, trees and every bird and beast and creeping thing. Buttercup, clover, gilia, Brodiaea, Allium, Dodecatheon, Larkspur, and portulacas are in flower. The oaks are in full leaf. A fine fragrant walk, the babies delighted."

"At Home on the Ranch (Martinez) April 12, 1895" John Muir, John of the Mountains: The Unpublished Journals of John Muir, edited by Linnie Marsh Wolfe University of Wisconsin Press, 1979.

In 1906 the People's Water Company began purchasing land in San Pablo and Bear Creek for watershed lands. This included the Blum property and the Bro~~ Ranch, which made up much of the former Rancho San Felipe. The East Bay Water Company, which acquired People's Water Company in 1916, constructed San Pablo Dam in 1923.

In 1928 the newly formed East Bay Municipal Utility District acquired the total holdings of East Bay Water Company and sold the lands outside the watershed as surplus land. In 1957 Contra Costa County and the East Bay Municipal Utility District agreed to a land conveyance that established large open-space park in the Bear Creek watershed, to be called Briones. In 1964 portions of Contra Costa County were annexed to the Park District. Following this annexation, the County and the Park District agreed to a transfer of County land to the District with further acquisition of lands to be carried out by the Park District. Since 1966, watershed lands and other acquisitions have combined to form the current Park boundaries, totalling over 5000 acres. Minor facilities were constructed by the Park District, and the Park was opened in 1968.

73 ANALYSIS/MANAGEMENT

Archaeology

All grading, especially near creeks, has the potential for uncovering archaeological resources. Areas where large grading projects, such as,a dam, are planned SA.ould be surveyed by registered archaeologists. For other grading, construction personnel and supervisors should be made aware of the potential for uncovering archaeological resources. If resources are uncovered, grading should be curtailed in that specific location until an archaeologist can get to the site.

History

The history of the Briones area is reflected in the naming of natural features and Park District trails and facilities. The interpretarive . activities for the Park should .include historic information. An interpretative theme for Brione$ should emphasize Spanish rancho life because programs in other District parklands do not focus on this period of Cal:i,fornia and Bay area history.

74 . V. PARKLAND DEVELOPMENTS

...... A. SERVICE ROADS AND TRAILS

-\. INVENTORY

Figure V. A-I: Itlmprovements" shows the existing trail and road system in Briones. Forty-six miles of roads and traill;! comprise the extensive system which provide excellent access to most areas of the Park.

The major use ofth~ Natural Unit is for hiking and horseback riding on trails which are considered colnp a t,ib Ie with resource preservation. Trail access into the Park is provided from the staging areas at the periphery of the Park. Mote local access trails from the surrounding communities will be open though subdivisioneasemen1;:s as adJgpent lands ar~ d.eveloped. Within the park there i.s an extensive service and 'fire road system whi~h comprises the majority of trails in the Park. Fire protection .at Briones is .. ,under the autj:1orityof the Contra Costa County Consolidated Fire District. According to their current standards all Briones fire trails shall be maintained at a 151 width. At the present time this applies to all Briones service roads.

Trails. this wide are not necessary for District maintenance reponsibilities and narrower roads are less costlY and less·unsightly. Therefore, the Plan suggests that the official fi·retqdl map be 'reviewed by the FBRPD and ecce Fire District and a hierarchy of trails be established. Any trails not necessary for fire protection should be maintained at an 8 1 to 10'width.

Certain trails are identified on the Plan as Regional Trail links. An east... west' link through Homestead Valley and Lafayette Ridge will connect the Briones to Tilden, Mt. Diablo and Las Trampas. A north-south link on Old Briones Road Trail and through Alhambra Valley will connect Briones to Martinez Regional Shoreline as well as the existing California Hiking and Riding Trail.

A few trails in Briones are designated as hiking and riding trails (no vehicles) to be maintained to a maximum 4' width by hand labor and small equipment. However,since these trails are much appreciated by trail users, yet require hand labor for maintenance, the Plan suggests that volunteer labor be sought to supplement Park staff.

75 ~ _BRI,?_I'U~~_~t:~~~I'J~L, tJA.,Ht\ Improvement~ . . ~O '1.000 . tnmLr=l . D'~I '~;;:-'.:.A::;;-:-:-;:-:~;~:----C: ",,,,-..,-0_- ..--. ~..~~~~=:J FIGURE V. A-l: IMPROVEMENTS

This map shows all man-made improvements which have been made to the Park •

...... , Sanitary Sewer ...... Water Line • • -..-Go •• Gas Li'lle -·-"'-·~E1ectric & Phone (overhead) i::-"--=,:::::Transmissio'll Lines (overhead) - - -~ !liking/Riding/Service Trails )( oK }" '" Fence q , ANALYSIS/MANAGEMENT

This section is directed at unpaved roads and trails.

Briones Par~ has an extensive system of roads and trails providi~g pedestrian, equestrian, and motor vehicle access. Narrow trails (18" wide), serving only hikers and equestrians comprise a small percentage of ,the whole system. Such trails endure relatively more severe use than wider ones because all users follow the sattle line. Maintenance of narrow trails is limited to hand labor, which is ata premium. Therefore, only a few such trails will be officially designated in the park, and use of unofficial trails will be passively discouraged through a policy of not mapping; signing, or maintaining them.

Slightly wider trails (3--4') can be more easily mai'lltained using diminutive mechanical equipment, and are somewhat less subjeat to wear due to the distribution of users acros.s the wider surface. However, no such trails are known to .exist in the park at present , and the existing road system, coupled with the limited foot trails, is seen as p";,oviding adequate access for park users and staff. Therefore, construction and maintenance of medium width trails is not anticipated.

Fire access roads comprise the major portion of tne Briones road/trail system, and will continue to do so into the foreseeable future. The existing pattern of roads is generally adequate, however, the specific alignments are not always favorable. The existing alignments evolved based on land ownership boundaries, convenient topography, and lack of adequate construction equipment. State and County fire laws require the 'annual clearance of vegetation from road surfaces, which is commonly accomplished during April and May by grading the surface with a motor grader. The combination of inadequate alignment and past poor grading practices has resulted in a road system with many drainage and erosion problems. It is District policy to correct these problems as time and equipment availability permit.

76 In general, two types of road drainage problems are encountered: 1) downslope berms on the side of roads, and 2) cuts over the crown of hills (see Figure V. A-'-2: "Road Cross Sections"). The general solution is to slope the roads (from side to side) to the outward or downhill edge, permitting water to flow off of the road surface throughout its length without building up a large volume of water. In many cases; this can be accomplished by cutting off the berm of material which has accumulated on the outside road edge to permit water to escape. In these circumstances the work can be done during the couse of regular grading, although sometimes several passee (seasons) may be required to .~ eliminate the entire buildup. One impact of eliminating the berm is the apparent widening of the roadway •. Contra Costa County ordinance requires that roads serving as fire access be 15 feet wide. District ~, grading practice is permissive of narrower roads (10-12'), provided passing sites (16-20' wide) are provided at approximately quarter-mile intervals. It is the intention of the District to meet these width standards on its fire access roads to the degree that topography permits. Where removal of the berm creates an excessively wide road, the road will not be graded to the toe of the cut bank, and bank slump will be permitted to accumulate until the appropriate road width is achieved. Another problem is that some fences are located immediately downhill of the road preventing berm removal. In these cases, the fence may need to be relocated. In a number of locations simple berm removal is an inadequate solution; major reshaping or complete realignment will be necessary to achieve the desired results. This work cannot be accomplished bya motor grader alone, and will necessarily require cons~derably more earth movement than mere grading. New alignments will be selected to provide favdrabl,e gradient (less than 15%), as well as drainage. Abandoned alignments will be reworked as necessary to eliminate drainage problems and provide a reasonably natural contour, and, where necessary, be reseeded or provided with erosion control features, or both. For a more detailed discussion of District road grading practices, refer to the District Grading Manual.

FIGURE V. A-2: ROAD CROSS SECTIONS

The figures indiCate problems which Briones service roads (trails) exhibj.t and solutions to these.

77 ·~ BRIONES REGIONAL PARK road cross~sections

The fpllowing road. cross sections exhibit problems caused by bad rou~ing or grading and their solutions.

PROBt.E:M 1

Road locatedalcmg· ceI).terof broad ridgetop. Berms cannot be adequately graded off. Through repeat,ed g.radingapderosion, road is ultimately cut deeply into hilltop.

SOLUTION 1

Road loc.ateddf~to side of ridge • Provides necessary r;idgetop access and tbe a'pility tQd:rCl.inof;f to the side~ ...... -., ...... 'pROBLEM 2A '- .... :.:. Road tipped intobillSidi.Water accumulatesagaiIlsttop. o~ .cutbank, theni~ns alongro4d ~ OCCaJ.ionally .necessary ,but ·SE!ne.rallycauses \. erosiori·probletrts .snd should be '\\ avoide.d ~ " Roads. in this.:. condition require n:tajorreshaping t::0cor.rect drainage ...

-..;. , .. PROBLEM 2B

Road slo.ped to out·side,btitwith berm on edge •.. Water is caught and held on road. by berm. Cutting off berm -. permits drainage. .

SOLUTION 2

Road tilted outward, clear shoulder permits water to drain. Outslope of 5-15%, depending on steepness of road ~.... '\... (steeper roads required greater \ outslope). A 9-inch drop across a 15'. \ , road equals 5%; a 27-inch drop across the same width equals 15%. I

B. FACILITIES

INVENTORY

Structures

Figure V. A-I: n-i;prove1l'.ents" shows Park facilities. Two houses are . ..., located within the Park boundaries. One is located at the end of Briones Road on a small knoll overlooking Alhambra Valley, and is currently utilized as a park residence. It is a single story, three bedroom home, covering approximately 1754 square feet, of cinder block and wood construction. Telephone and electricity are available, and_ water is supplied to the home from a spring approximately 1~ miles away, through a 10,000 gallon redwood water tank located uphill from the . house. This tank also provides drinking water at the end of Briones Road. Sewage is disposed of through a septic system. The other home is located off Alhambra Valley Road. It is a small (737 square fee-t) , one story, two bedroom home of frame construction. Municipal water, telephone and electricity are available, and sewage is disposed of through a septic system. Natural gas is supplied by storage tanks. In addition, there is a carport with attached shed and work area, which is currently utilized as a service yard.

A corral which is used by the grazing tenant in the Park is located in BearCre~kVal.ley. ThePprk is fenced into a number of large pastures for grazing purposes.

Recreation Facilities

Since opening in 1967, limited recreational facilities have been provided in the Park. These are located near tHe Bear Creek entrance. At the parking lot is' a fbur~acre meadow and two picnic areas with approximately 20 tables. Adjacent to this development is a children's play area with sand, climbing logs and slide. Bear Creek Valley isa major trailhead. North of Bear Creek Valley, in Abrigo Valley, are two day camp centers with large shade structures. The southern (Maud Whalen) camp is provided with water from a 10,000 gallon capacity redwood tank; the northern (Wee-ta-chi) camp is supplied from a small (1000 gallon) tank. Chemical toilets are provided. Southeast of Bear Creek Valley, in Homestead Valley, is a roving archery range put in and run by the Briones Archery Club.

There are no recreation facilities a.t the northern end of the Park other than a trailhead ori Briones Road near the Park residence. However, recent acquisitions of flat meadow areas at the periphery of the Park present opportunities for providing additional recreational facilities here.

78 ANALYSIS/MANAGEMENT

Potential development sites in Briones are found on ground of gentle slopes. Vegetation removal of grass is generally preferrable to removal of trees or brush from a wildlife standpoint. Figure V. B-1: ",Potential Development Sites" shows areas with this characteristic.

The standardization of signing and color schemes for various materials assures continuity and guided maintenance for existing facilities. The . '-;::; District's Central Stores carry only the approved materials that are available to Park maintenance crews. Any proposed variation from standards would have to be approved by the Planning and Design Department.

c. UTILITIES

INVENTORY

Two major utility lines cross the Park and others serve points within it, which are shown in Figure V. A-I: "Improvements". Development of Tavan Estates has brought municipal water (City of Martinez 12-inch main) and sewer (CCCSD 8-inchmain) to the eastern boundary of the Park. The city can serve users up to 300 foot elevation without pumping. The City also has a 6-inch main in Alhambra Valley Road to the eastern end of the adjacent Fry property, and a 2-inch water line off this main serves the service yard and adjacent residence. No municipal water is readily available to other areas of the Park. Telephone and electrical lines serve both residences in the Park.

ANALYSIS/MANAGEHENT

The sanitation and water management specialists are working closely with the Park crews, and will continue to do so in order to assure proper preventive maintenance of utilities in the Park.

79 BRIONt:~ Ht:uIUNAL ·tJAH~ ; potentia. - , . ..~ -.- .. ------.--- _. --.. ... i'. . , . CONTOUR INTERVAL 80 FEET . m\tJ .... t.'t . . 0 '. dey. sites FIGURE V. B-1: POTENTIAL DEVELOPMENT SITES

This figure shows the areas of Briones which meet the slope and vegetation criteria for development •

..~~ 0-10% Slope & Grass - High Potential

0-10% Slope & Brush - Moderate Potential

0-10% Slope & Forest ~ Low Potential

£:::] Over 10% Slope or Above 1000 i Elevation IIIllExisting Urban

80 VI. ACQUISITION, OWNERSHIP, LEGAL AGREEMENTS

A. PARKLAND ACQUISITION HISTORY

i, Figure VI. A-I: Parkland Acquisition shows the parcel boundaries, dates, and acreages for past land acquisition~. The total amount spent on acquisition of Briones between 1966 and 1981 is slightly more than three million dollars.

Formation of Briones began in 1957 with acquisition of the upper reaches of Briones Creek and its surrounding ridges from East Bay Municipal Utility District for a country park. In 1966 the property was transferred to East Bay Regional Park District. The park size doubled in 1965 with the addition of the Townsend Ranch, which included the Briones Crest, Sindicich and Maricich Lagoons and the upper reaches of Alhambra Creek. In 1967 the District bought an area near Bear Creek Road from EBMUD on which was constructed the Bear Creek Staging Area and picnic meadow. Briones Road was subsequently closed to its present limits.

Briones was designated for considerable expansion in 1973 when the then Master Plan was adopted, and shortly after the District taxing power was doubled. The priority of the program was to acquire a northern access with day use facilities, particularly for residents in the Martinez/Concord side of the Park. In 1973 the Hirschkind pr0I>erty was purchased which fronted Alhambra Valley Road and in 1975 the Lockwood property was purchased which did not have road .frontage but did have an semi-enclosed area, Alhambra Creek Valley, ideal for the development of recreational facilities and parking. Acquisition of an access to Reliez Valley Road is not complete but portions were acquired in 1980 and 1981 from the Martinez Unified School District and PG&E, respectively.

FIGURE VI. A-I: ACQUISITION

This map shows parcels acquired, acquisition year, and approximate acres of acquisition.

Protection and preservation of Lafayette Ridge provided the reason for purchase of Panorama Ranch in 1976. Two parcels on the ridge are currently o,vued by the City of Lafayette and will be dedicated to the District in the future. Two other pieces, the Girl Scout Parcel and the Brown Parcel were purchased in 1978. The Brown Property provides an

81 ~ IjHIUNI::~ Hl::ulUNAL t" AHr\. a.cqulSltlon area suitable for a staging area for the Park as well as for the Briones/Mt.·Diablo Regional Trail and Briones/Las Trampas Regional Trail and the.link to the Briones to Tilden Trail Acquisition. The remaining section along the ridge is anticipated in the summer of 1981.

Over 800 acres of parkland in the eastern side were acquired largely at reduced cost (less than market value) in 1977-78 from Shapell Industries who developed the flat lands. This acquisition added valuable wooded eastern slopes to the Park, and provided a trail staging site off Reliez Valley Road.

In 1981, acquisitions of the Martinez School property (13 acres) and the PG&E property (25 acres) were completed at the north end of Briones. A ~ . dedication of property (about 36 acres) on Lafayette Ridge is expected soon to complete trail access from the Bro~ p~operty to the main body of the Park. Addit.ional acquisition is needed at the north end of Briones, if access is to be gained fromReliez Valley Road to Alhambra Creek Valley.

A few ridges and portions of watersheds surrounding the Park on the northwest corner, the northwest side and on Lafayette Ridge are not within the Park. Development of these ridges and slopes would impair the park experience for hikers in the Natural Area and also impact the youth group camping facilities in Abrigo Valley. Anadditional consideration is that the waters flow into the Park and water quality, especially sediment, could be affected. Completion of access at Alhambra Creek Valley and Lafayette Ridge are important.

B. OWNERSHIP

INVENTORY

Briones Regional Park'is owned in fee by the Park·District. Additional parcels will become parkland in the near future. They have been accepted by Board connnitment, but title has not been obtained.

BRIONES ASSESSOR'S PARCEL NUMBERS

167-202-17 365-130-08 365-190-01 - 365-220-11 -27 -11 365-200-01 -25 -06 -02 365-230-28 -26 -09 -03 -05 -05 -10 -06 , 231-080-03 -09 -33 365-150-31 -08 245-110-04 -07 365-180-04 -06 365-070-04 -02 -05 -02 -01 -04

82 C. EASEMENTS, WATER RIGHTS, AND OTHER LEGAL AGREEMENTS

Certain parcels of Briones Park are subject to existing easements, water rights, and other legal agreements. These include several utility easements, which are shown in Figure V. A-I: Improvements.

(1) A IOO-foot wide easement for major high voltage (230KV) transmission lines by Pacific Gas and Electric Company is at the north end of the park .

. '" (2) A 20-foot wide easement by Pacific Gas and Electric Company (successor to Coast Counties Gas and Electric Company) contains a lO-inch buried gas line on the eastern side of the park.

(3) Easements for pole lines serving tile two residences are within the park and the property inholding near the service yard.

(4) In the Bear Creek watershed (which is a public water supply watershed), the East Bay Municipal Utility District must approve all plans, specifications, and locations of sewage disposal.systems and use of onsite water. EBMUD also reserves mineral rights and retains the right to perform.erosion control measures. The Bear Creek watershed area is shc;>wn in Figure IV. B-1: . Hydrology.

(5) AI:l existing water tunnel in Alhambra Creek Cap.yon provides water for several residences along Reliez ValleyRoadthrougl:). a pipeline running down the Alhambra Creek. The water rights to the tunnel spring are controlled by this residences.

(6) The District holds a trail easement into the Park from Tavan Estates.

(7) Mr. Brown holds a life estate for use of the Brown property.

83 VII. REPORT PREPARATION AND PERSONS CONTACTED

A. REPORT PREPARATION

The Resource Analysis/Management Plan has been prepared by the East Bay ~egional Park District under the direction of the Board of Directors; Richard Trudeau, General Manager; Jerry Kent, Assistant General Manager; Lewis Crutcher, Chief, Planning and Design; and Peter Koos, Landscape Architect. The principal author and editor of this report was Roger Wilde, Environmental Coordinator/Resource Analyst. The 1976 Briones Resource Analysis was prepared by Neil Havlik.

Other major contributors to this document were: Steve Edwards, Jeanie Perkins, and Neil Havlik (Geology and Archaeology); Ken Burger (Hydrology and Water Quality); Bert Johnson, Neil Havlik, Walter Knight, and Roberta Moreland (Plant Ecology, Vegetation and Flora); Robert Stebbins, Jeff Wilson, Ron Russo, Steve Abbors, Scott Miner, and Reginald Barrett (Wildlife Habitat and Fauna); Roberta Moreland, and Rich Aronson (Wildfire); Neil Havlik (Range); John Nicoles and Bob Doyle (Roads and Trails); Neil Havlik and Peter Koos (Facilities and Utilities); and Carol Thompson, June Miller, and Mark Taber (Land Acquisition History). Graphics for the document were prepared by Karen Parsons, Tim Coates, and Walter Mahoney. Photographs taken by Monte Monteagle. Word processing done by Marilyn Thurau.

The District acknowledges contributions made to this report by the following persons and agencies: Chuck Hendersoh, Roger Wilde, Walter Mahoney, Susan Hagan and Margaret Gorsky, East Bay Regional Information System (EBRIS); Northwest Regional Office, California Archaeologic Site Survey, Sonoma State University; Bob Nuzum, East Bay Municipal Utility District; Roberta Moreland, B.A. S. I. S Program, Association of Bay Area Governments (Landsat, earthquake and resource data); Paul Wilson, Roberta Moreland, and Annie , GEOGROUP (computer analysis and mapping); Wilson, Ihrig & Associates (acoustical consultants); and ·Pacific Aerial Survey (aerial photographs).

84 B. PERSONS CONTACTED

EAST BAY REGIONAL PARK DISTRICT

Eakin, Dave, Superintendent of Operations Emanuelson, Ron, Briones Park Supervisor Horbach, Bud, Operations Zone 1 Manager Hornbeck, Hulet,-- Chief, Land Department Kinney, Jack, Briones Park Worker Nuzum, Bob, Former Water Specialist Owen, Bob, Chief, Administration Reeves, Harry, Former Range Specialist

OTHER AGENCIES

Aho, John, U. S. National Park Service Booth, Jack, California Department of Fish and Game Kelly, Paul, Region 3, California Department of Fish and Game Martinez, Art, East Bay Municipal Utility District Nuzum, Bob, East Bay Municipal Utility District Oliveri, Adam, Sanitary Engineer, California Regional Water Quality Control Board, Region Ritchie, ,Water Resources Engineer, Department of Water Resources, Sacramento Sanders, Dale, Contra Costa County Planning Department. Stein, Dick, Hydrologic Engineer, East Bay Municipal Utility District. York, Rick. California Natural Diversity Data Base.

INDIVIDUALS

Davis, John Nelson, Ted Smyth, Jim Stein, Louis L., Jr. Wagner, Ross

85 VIII. BIBLIOGRAPHY

Aronson, C. Richard. East Bay Regional Park District Fire Department . " Operations Manual. 1978.

, 1981 Bay Area Spatial Information System (BASIS) Data Base, <, . Association of Bay Area Governments.

, Briones Regional Park Resource Analysis. Planning and Design Department, East Bay Regional Park District. 1976.

, Climatic Summary of the United States--California, U. S. Department of Commerce, Weather Bureau. 1964.

Collier, George. Mexican Land Grant Cases in Contra Costa County, California. 1976

, Contra Costa County General Soil Survey & Report. Contra Costa Soil Conservation District. 1968.

Dibble, Thomas W., Jr., Preliminary Geologic Map of the Briones Valley Quadrangle, Alameda and Contra Costa Counties, CA, U.S. Geological Survey Open File Report, 1980.

, 1981 East Bay Regional Information Systems (EBRIS) Data Base, East Bay Regional Park District and University of California.

Ferguson, Kathleen. Rare, Endangered, and Depleted Plant and Animal Species, Contra Costa County, California. Pkepared for Contra Costa County. May, 1981:

--, "Flatland Deposits of ", U.S. Geological Survey Professional Paper 944.

Foley, Robert J. Appraisal Report, Briones Expansion, Hirschkind Property, Alhambra Valley, Martinez, California. 1974.

Gaidula, Peter, Wildland Fuel Management Guidelines for the California State Park System. State of California, The Resources Agency, Department of Parks and Recreation. August, 1976; reprinted May, 1977 .

Gas and Electric Line Maps. Pacific Gas and Electric Company.

, Geologic Hazards Map. Contra Costa County Planning Department. 1976.

86 Johnson, Bert. "Botany of Briones", from The Story of Briones. 1978.

Knight, Walter, ed. The Story of Briones. 1978.

Lease Agreements. East Bay Regional Park District.

, Location Reports Map; Rare Endangered or Locally Depleted Species, Contra Costa County Planning Department. 1976.

1973 Master Plan:- East Bay Regional Park District.

1980 Revised Master Plan. East Bay Regional Park District.

Munz, Philip A. & Keck, David D. A California Flora. University of Califo_rnia Press, 1959.

Nicoles, John. EBRPD Grading Manual. East Bay Regional Park District, 1980.

Nicoles, John. EBRPD Vegetation Management: Principles and Policies. East Bay Regional Park District. 1976.

Olson, Jana. EBRPD A Trail Manual. East Bay Regional Park District,

Park Operations Manual. East Bay Regional Park District. 1980.

Pease, M. H., Jr. Geology of the Sobrante Anticline & Vicinity, Briones Quadrangle, Contra Costa County, California. 1954.

Purcell, Mae Fisher. History of Contra Costa County 1940. 1976.

Rainfall Maps. Contra Costa County Planning Department. 1976.

Sands, Anne, Ed., Riparian Forests in California. Institue of Ecology Publication No. 15. Davis, California. May 14, 1977.

, "San Francisco Sheet", Geologic Map of California, California State Department of Natural Resources. 1961.

, Soil Survey of Contra Costa County. U. S. Soil Conservation Service. September, 1977.

Stebbins, Robert C., "Use of Habitats in the East Bay Regional Parks by Free-living Vertebrate Animals", August 11, 1975. From Nicholes, Vegetation Management: Principles and Policies, East Bay Regional Park District, 1976.

Strentzel, Louisiana. "Diary of Louisiana Strentzel", 1878. Unpublished, available at John Muir House National Historic Site, National Park Service. Martinez, California.

Title Deeds. East Bay Regional Park District.

87 Wallace, Lawrence. Appraisal for East Bay Regional Park District, Townsend Ranch, Contra Costa County, California. 1964.

, Water Resources Development in Briones Regional Park, Water Resources Engineers, Inc. 1967.

Water and Sewer Main Maps. City of Martinez Engineering Department.

Wolfe, Linnie Mar-Sh. "At Home on the Ranch, April 12, 1895 11 • John of the Mountains: The Unpublished Journals of John Muir. University of Wisconsin Press. 1979.

88 .",